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Multi-environment wheat trials provide valuable information on the extent of genotype x environment interaction, the stability of genotypes and define and confirm agro-ecological regions through associations among sites. The All India Coordinated Crop Improvement Project on wheat evaluates candidates for release across the wheat growing regions of India. To facilitate this process the wheat area is divided into six agro-ecological zones; the northwestern plains zone (NWPZ), the northeastern plains zone (NEPZ), the central zone (CZ), the peninsular zone (PZ), the northern hills zone (NHZ) and the southern hills zone (SHZ). Factor analytic (FA) models were used to analyze the genotype x environment interaction for yield of 813 wheat genotypes evaluated at 136 locations across the six agro-ecological zones in 1307 individual advanced variety trials between 2008/09 and 2012/13. Genotype x environment interaction was firstly assessed separately within each of the six established agro-ecological zones. Key locations with a high genetic correlation with all other locations within each zone were identified. Predicted genetic values of important cultivars that were represented in a wider range of environments within each zone were estimated and highly stable genotypes were found. Genotype x environment interaction was subsequently assessed across agro-ecological zones. Only those environments where the models accounted for > 99% of the genetic variance were retained for further analysis and two smaller zones (NHZ and SHZ) with little or no genotype congruence with other agro-ecological zones were removed. Thus 476 genotypes from 488 environments were included in the analysis. Fifteen clusters of environments with similar patterns of adaptation were found. These clusters were then characterized based on zonal classification, sowing time, irrigation regime, latitude and year and three regions broadly representing the main wheat growing areas of India were identified. These regions represent a combination of the NWPZ and NEPZ defined by latitude, a central region that combines CZ locations with northern PZ locations and a southern region comprised of southern PZ sites. Further stratification of these zones was then possible based on sowing time and irrigation practice. One cluster of 29 environments had a high average genetic correlation (r = 0.75) with most other environments and production zones. These represent key locations where larger numbers of entries might be grown in future seasons as they are the best predictors of yield across cropping zones.

With 1 figure and 5 tables Abstract Two winter alleles of Vrn-A1 were recently found in wheat cultivars adapted to the Great Plains of the USA. Using a diagnostic marker for a single-nucleotide polymorphism (SNP) in exon 4, which distinguishes the alleles, the allele in the Great Plains cultivar ‘Jagger’ was common in Australian and CIMMYT cultivars, but ‘Veery’ cultivars carried the alternate allele from their Russian ancestor, which was the same as the allele in the Great Plains cultivar ‘Wichita’. The ‘Wichita’ allele was in North American winter cultivars, and chromosome substitution lines with a high level of tolerance to freezing, but not in substitution lines with a lower level of tolerance. The SNP between the alleles alters the predicted Vrn-A1 protein sequence, and this potentially explains differences in freezing tolerance. We suggest that these winter alleles could be coded as Vrn-A1v for the ‘Jagger’ allele and Vrn-A1w for the ‘Wichita’ allele. Cultivars with the spring Vrn-A1a or Vrn-A1b alleles carried the same SNP allele as ‘Jagger’, suggesting that the mutation from winter to spring for these alleles occurred in a Vrn-A1v genotype.

Fenugreek (Trigonella foenum-graecum L.) is a minor crop in Australia with potential for seed, forage and green manuring, with most production based on an unnamed cultivar (A150000). A germplasm collection of 205 fenugreek accessions was evaluated in the field in south-eastern Australia for a range of phenotypic traits. There was significant variation exhibited for all traits including growth habit, flowering time, seed colour, seed size, biomass and seed yield. Over 100 accessions had significantly higher yield and/or biomass than the currently grown A150000. The diversity exhibited provides a promising basis for a genetic improvement program in Australia and in similar environments in other countries. The accessions identified as from the subspecies indica Sinsk. had small, yellow seed and originated mainly from Pakistan and India and half of these types had significantly higher yields than the check-line. Accessions that fitted the description of the more diverse subsp. foenum-graecum were from Iran, Afghanistan, Turkey and several northern African countries, and there were high yielding green-seeded types in this group. Accessions from Turkey and Iran showed the most phenotypic diversity. High yielding accessions were found in germplasm from most countries and all latitude zones, although latitudes >30° provided 73% of the high yielding accessions. Countries of origin warranting further investigation at the mid-30s latitudes are Morocco, Iran, Turkey, Algeria and Jordan. It was concluded that traits associated with high yielding lines with yellow or green seed can be found in different centres of origins.

Fr-B2 is a complex locus on chromosome 5B that affects frost tolerance, days to heading, grain yield and probably other traits of commercial importance in wheat (Triticum aestivum L.). It interacts epistatically with other major genes, especially VRN1. There are two known alleles of Fr-B2: an intact, wild-type allele, and an allele with a large deletion. Published methods for identifying these alleles are slow and expensive, making the development of a high-throughput, co-dominant SNP (single-nucleotide polymorphism) marker highly desirable, especially for commercial wheat breeding. A diverse panel of cultivars and breeding lines was characterised for SNPs and alleles of Fr-B2. Four SNP markers co-segregated as a haplotype block with Fr-B2 across unrelated cultivars and related backcrosses differing for alleles of Fr-B2. A robust KASP (Kompetitive allele-specific PCR) assay was developed for one of the SNPs, KASP_IWB26333, which should facilitate the inclusion of Fr-B2 on genotyping platforms for breeding and research.

Phasic development of wheat is largely determined by the interaction of the VRN1 and PPD1 genes with vernalising temperature and photoperiod. VRN1 and PPD1 are regulatory genes, known to influence freezing tolerance, plant morphology and grain yield as well as phasic development. Forty-seven doubled-haploid lines were characterised for Ppd-B1, Ppd-D1, Vrn-A1, Vrn-B1 and Vrn-D1 to determine the effect of allelic combinations of these genes on timing of anthesis and crop growth rate. The lines were grown in replicated field experiments at two locations in Australia. The VRN1 and PPD1 genes accounted for 75% of the genetic variation for time from sowing to anthesis. Vrn-A1 and Vrn-B1 similarly affected time to anthesis, but only Vrn-B1 affected crop growth rate, with the spring Vrn-B1a allele resulting in faster crop growth rates than the winter Vrn-B1v allele. This suggests that the effect of Vrn-B1 on crop growth rate is not a direct consequence of its effect on development per se, but rather due to its influence on other physiological processes. The faster growth associated with Vrn-B1a may explain the high grain yield of cultivars with this allele in some environments, as shown in a previous study.

The races of maize (Zea mays L.) which are cultivated in the highlands of central Mexico at altitudes above 2000 m include Palomero Toluqueno, Conico, Arrocillo Amarillo, Chalqueno, and Cacahuacintle. This complex of races is of ancient origin and has a distinct plant morphology, karyotype, and isozyme frequency compared to other types of maize except, possibly, some races from the highlands of Guatemala. It is adapted to cool areas with mean growing season temperatures between about 12.5 and 17.0 o C and is superior to maize from temperate, mid-altitude tropical, and lowland tropical regions for seedling emergence, photosynthetically-based growth, and ability to continue grain filling at low temperatures (.)

A variety cross diallel of five populations of maize (Zea mays L.) was evaluated in a cool, temperate environment. Two of the parental populations were Corn Belt Dent synthetics (AS3 and BS22), one was developed from selected lines from a CIMMYT population developed for highland regions of the tropics and four Corn Belt Dent inbred lines (NZS3), and the other two had the pedigrees ‘Criollo de Toluca’× AS32 (NZS1) and ‘San Geronimo’× BS222 (NZS2). ‘Criollo de Toluca’ is from the highlands of Mexico and ‘San Geronimo’ is from the highlands of Peru. The objective was to study the influence of introgressing highland tropical germplasm into elite Corn Belt Dent synthetics on genetic effects, especially inbreeding depression, and to develop recommendations for the utilization of the introgressed populations. Inbreeding depression explained the greatest proportion of the variation among entries for grain yield, days to silking and plant height, but not for grain moisture at harvest and root lodging. For grain yield, NZS1, NZS2, and NZS3 had high levels of inbreeding depression and the difference between NZS1 and AS3 was statistically significant. High levels of root lodging were associated with NZS1 and high grain moisture at harvest with NZS2. These results indicate that a recurrent selection method, such as S1 selection, which effectively reduces inbreeding depression, should be used in early cycles of selection with introgressed populations containing highland tropical germplasm.

A visual growth score method was used to monitor the growth performance of 24 populations of white clover (Trifolium repens) over a three year period. The mean growth scores for each year were used as population x year data for cluster analyses. Cluster analysis methods based on a regression model where genotypes were grouped for similarity of both intercepts and slopes (Method 1) or slopes only (Method 2), were able to differentiate the persistent populations from those that showed a yield decline over time. The deviations from regression mean square was used as an indication of stability. Method 1 was able to cluster the high yielding persistent populations into a separate cluster, thus facilitating the selection of desirable populations. Deviations from regression identified the stable populations from the cluster. In combination with the simple growth score system, this analytical method is a powerful tool for evaluating a large number of breeding families of perennial pasture clovers and grasses for yield and persistence.

A diallel cross of six inbred lines of maize (Zea mays L.) from the Corn Belt of the USA and one inbred line (NZ1A) with characteristics of maize from the highlands of Mexico was grown in a cool, temperate environment. The objective was to investigate interrelationships and combining abilities of plant development traits likely to influence the time required to reach low ear moistures in the field. The traits were days to silking, days to physiological maturity, ear moisture at physiological maturity, grain filling duration and ear drying rate after physiological maturity. Grain yield and grain moisture at harvest were also considered. Differences among the hybrids of this diallel cross for ear and grain moisture at the usual harvest time were largely determined by differences in ear drying rate after physiological maturity, and not by differences in days to silking, days to physiological maturity, or in ear moisture at physiological maturity. General combining ability (GCA) effects were much larger than specific combining ability (SCA) effects for all traits. NZ1A had positive GCA effects for grain filling duration and negative GCA effects for ear moisture at physiological maturity which were outside the range of the Corn Belt lines suggesting that this line, or similar Mexican germplasm, could be useful for developing hybrids with high grain yields and low ear moistures at harvest in cool, temperate environments.

FROST RESISTANCE 2 (FR2) genes of wheat are C-Repeat Binding Factor (CBF) genes with two major alleles known for both Fr-A2 (‘T’ and ‘S’) and Fr-B2 (‘WT’ and ‘DEL’). VERNALIZATION 1 (VRN1) genes have a regulatory role on CBF genes, with known epistatic interactions between Vrn-A1 and Fr-A2 for tolerance to freezing temperatures during vegetative growth. VRN1 genes were also known to affect days to heading and grain yield. Therefore, FR2 genes might also affect these traits. A wide range of cultivars was characterised for VRN1, Fr-A2 and Fr-B2 genes. A third allele of Fr-A2 was found in cvv Excalibur and Axe. The winter cultivar Norstar, which was known to have a high level of frost tolerance during vegetative growth, had the combination Vrn-A1w + Fr-A2T + Fr-B2WT, as did a spring landrace from Afghanistan that was known to have superior tolerance to frost during reproductive development. No Australian spring cultivar was found with this combination, but it could be selected from crosses between adapted cultivars. This would enable the role of VRN1 and FR2 alleles in reproductive frost tolerance to be evaluated in an adapted background. Using large, existing, plant-breeding datasets, the T allele of Fr-A2 delayed heading relative to the S allele, and the WT allele of Fr-B2 delayed heading relative to the DEL allele, but only in combination with particular alleles of the VRN1 genes. Fr-B2 affected grain yield, with the highest grain yields for spring lines produced by Fr-B2DEL in combination with the spring allele of Vrn-B1.

A backcross population (NZS1) of maize (Zea mays L.) was produced by crossing a highland Mexican population with the elite Corn Belt Dent synthetic AS3, and then by backcrossing to AS3. S1 lines, S2 lines, and S2 testcrosses with an elite tester were used to compare the means, correlations, genetic variances, and predicted gains from selection of NZS1 and AS3 for grain yield, grain moisture at harvest, root and stalk lodging in a cool, temperate environment in New Zealand. The S1 and S2 lines from NZS1 had lower mean grain yields, higher levels of root lodging and higher mean grain moistures than the S1 and S2 lines from AS3. Mean grain yields of testcrosses of NZS1 and AS3 were similar, but NZS1 testcrosses had higher levels of root lodging. Genotypic variances estimated from S1 and S2 lines were larger for grain yield and root lodging for NZS1, smaller for grain moisture, and similar for stalk lodging. Predicted gains from selection for grain yield using intrapopulation methods based on the additive-genetic variance were larger for NZS1, but predicted gains for testcross selection were similar for the two populations. Lines with high combining ability for grain yield and acceptable grain moisture in combination with the tester occurred in NZS1. Because of the higher additive-genetic variance and the occurrence of lines with high combining ability for grain yield, we concluded that populations including highland Mexican germ plasm should be valuable for recurrent selection programs in New Zealand and in other cool, temperate regions.

Grain yield forms one of the key economic drivers behind a successful wheat (Triticum aestivum L.) cropping enterprise and is consequently a major target for wheat breeding programmes. However, due to its complex nature, little is known regarding the genetic control of grain yield. A doubled-haploid population, comprising 182 individuals, produced from a cross between two cultivars 'Trident' and 'Molineux', was used to construct a linkage map based largely on microsatellite molecular makers. 'Trident' represents a lineage of wheat varieties from southern Australia that has achieved consistently high relative grain yield across a range of environments. In comparison, 'Molineux' would be rated as a variety with low to moderate grain yield. The doubled-haploid population was grown from 2002 to 2005 in replicated field experiments at a range of environments across the southern Australian wheat belt. In total, grain yield data were recorded for the population at 18 site-year combinations. Grain yield components were also measured at three of these environments. Many loci previously found to be involved in the control of plant height, rust resistance and ear-emergence were found to influence grain yield and grain yield components in this population. An additional nine QTL, apparently unrelated to these traits, were also associated with grain yield. A QTL associated with grain yield on chromosome 1B, with no significant relationship with plant height, ear-emergence or rust resistance, was detected (LODor =2) at eight of the 18 environments. The mean yield, across 18 environments, of individuals carrying the 'Molineux' allele at the 1B locus was 4.8% higher than the mean grain yield of those lines carrying the 'Trident' allele at this locus. Another QTL identified on chromosome 4D was also associated with overall gain yield at six of the 18 environments. Of the nine grain yield QTL not shown to be associated with plant height, phenology or rust resistance, two were located near QTL associated with grain yield components. A third QTL, associated with grain yield components at each of the environments used for testing, was located on chromosome 7D. However, this QTL was not associated with grain yield at any of the environments. The implications of these findings on marker-assisted selection for grain yield are discussed.

The grain yield of wheat is influenced by genotype, environment and genotype-by-environment interaction. A mapping population consisting of 182 doubled haploid progeny derived from a cross between the southern Australian varieties 'Trident' and 'Molineux', was used to characterise the interaction of previously mapped grain yield quantitative trait locus (QTL) with specific environmental covariables. Environments (17) used for grain yield assessment were characterised for latitude, rainfall, various temperature-based variables and stripe rust infection severity. The number of days in the growing season in which the maximum temperature exceeded 30 degrees C was identified as the variable with the largest effect on site mean grain yield. However, the greatest QTL-by-environmental covariable interactions were observed with the severity of stripe rust infection. The rust resistance allele at the Lr37/Sr38/Yr17 locus had the greatest positive effect on grain yield when an environment experienced a combination of high-stripe rust infection and cool days. The grain yield QTL, QGyld.agt-4D, showed a very similar QTL-by-environment covariable interaction pattern to the Lr37/Sr38/Yr17 locus, suggesting a possible role in rust resistance or tolerance. Another putative grain yield per se QTL, QGyld.agt-1B, displayed interactions with the quantity of winter and spring rainfall, the number of days in which the maximum temperature exceeded 30 degrees C, and the number of days with a minimum temperature below 10 degrees C. However, no cross-over interaction effect was observed for this locus, and the 'Molineux' allele remained associated with higher grain yield in response to all environmental covariables. The results presented here confirm that QGyld.agt-1B may be a prime candidate for marker-assisted selection for improved grain yield and wide adaptation in wheat. The benefit of analysing the interaction of QTL and environmental covariables, such as employed here, is discussed.

The cereal cyst nematode (CCN; Heterodera avenae), a root disease of cereal crops, is a major economic constraint in many wheat (Triticum aestivum)-growing areas of the world. The objective of this study was to assess the impact of the Cre1, Cre8 and Cre3 genes on CCN resistance. A population of 92 doubled-haploid (DH) lines derived from a cross between wheat cvs. Frame and Silverstar as well as 1,851 wheat breeding lines were screened for CCN resistance at the Primary Industries Research Victoria (PIRVic). A second population of 9,470 wheat breeding lines was screened at the South Australian Research and Development Institute (SARDI). Cre3 had the largest impact on reducing the number of female cysts, followed by Cre1 and Cre8. There was no significant difference in number of cysts between DH lines with or without the Cre8 marker, suggesting that the marker is not perfectly linked to Cre8. The estimated heritabilities were 0.32 in the DH population, 0.48 in the PIRVic data set and 0.32 in the SARDI data set, which confirm that this is a trait of low heritability. The repeatability of CCN resistance improved with an increase in the number of plants assessed per line—up to ten. However, 85–88% of the improvement was achieved with the assessments of the first five plants.

The Gpc-B1 gene from wild emmer has been proposed as a potential mechanism for improving grain protein in bread wheat without reducing grain yield. Near-isolines with and without the Gpc-B1 gene in three Australian-adapted genetic backgrounds, Gladius, Wyalkatchem and VR1128, were compared in 14 experiments across the south and west of Australia for grain yield, grain protein content and grain weight. The donor parents of Gpc-B1 were the Canadian cultivars Burnside and Somerset. One of the 14 experiments was discarded because of inadequate rust control and confounding effects of Yr36, a gene closely linked to Gpc-B1. Heading date and test weight were measured in five experiments. Across all comparisons, Gpc-B1 increased grain protein content and reduced grain weight, with a negligible effect on grain yield. Selected lines containing Gpc-B1 in a Wyalkatchem background had comparable grain yields to the elite cultivar Mace, but with significantly higher grain protein contents, slightly higher grain weights, similar heading dates and acceptable test weights. The development of agronomically acceptable lines containing Gpc-B1 was partially attributed to the removal of undesirable genes from wild emmer during the breeding of the Canadian donor parents and the use of Australian recurrent parents with high test weights.

Photoperiod and vernalisation genes are important for the adaptation of wheat to variable environments. Previously, using diagnostic markers and a large, unbalanced dataset from southern Australia, we estimated the effects on days to heading of frequent alleles of Vrn-A1, Vrn-B1, and Vrn-D1, and also two allelic classes of Ppd-D1. These genes accounted for ~45% of the genotypic variance for that trait. We now extend these analyses to further alleles of Ppd-D1, and four alleles of Ppd-B1 associated with copy number. Variation in copy number of Ppd-B1 occurred in our population, with one to four linked copies present. Additionally, in rare instances, the Ppd-B1 gene was absent (a null allele). The one-copy allele, which we labelled Ppd-B1b, and the three-copy allele, which we labelled Ppd-B1a, occurred through a century of wheat breeding, and are still frequent. With several distinct progenitors, the one-copy allele might not be homogenous. The two-copy allele, which we labelled Ppd-B1d, was generally introduced from WW15 (syn. Anza), and the four-copy allele, which we labelled Ppd-B1c, came from Chinese Spring. In paired comparisons, Ppd-B1a and Ppd-B1c reduced days to heading, but Ppd-B1d increased days to heading. Ppd-D1a, with a promoter deletion, Ppd-D1d, with a deletion in Exon 7, and Ppd-D1b, the intact allele, were frequent in modern Australian germplasm. Differences between Ppd-D1a and Ppd-D1d for days to heading under our field conditions depended on alleles of the vernalisation genes, confirming our previous report of large epistatic interactions between these classes of genes. The Ppd-D1b allele conferred a photoperiod response that might be useful for developing cultivars with closer to optimal heading dates from variable sowing dates. Inclusion of Ppd-B1 genotypes, and more precise resolution of Ppd-D1, increased the proportion of the genotypic variance attributed to these vernalisation and photoperiod genes to ~53%.

Grain quality is an important determinant of market value of wheat in southern Australia and in many other parts of the world. Identification of the genes that influence grain quality traits and estimation of effects of alleles of these genes can improve the effectiveness of wheat breeding. An efficient method for estimating the effects of alleles of recently discovered genes is to use mixed-model analyses in large plant breeding datasets that have already been characterised for previously known genes. We used this method to estimate the effects of two alleles of Spa-B1, a storage protein activator gene that is linked to Glu-B1, on grain quality traits. Alleles of the two genes tracked together as haplotypes for generations, but recombination events were identified. These recombination events were used to enhance confidence in identification of the alleles. The effects of the alleles of Spa-B1 were small and statistically not significant for all of the grain quality traits in our population.

Photoperiod and vernalization genes are important for the optimal adaptation of wheat to different environments. Diagnostic markers are now available for Vrn-A1, Vrn-B1, Vrn-D1 and Ppd-D1, with all four genes variable in southern Australian wheat-breeding programs. To estimate the effects of these genes on days to heading we used data from 128 field experiments spanning 24 years. From an analysis of 1085 homozygous cultivars and breeding lines, allelic variation for these four genes accounted for ~45% of the genotypic variance for days to heading. In the presence of the photoperiod-insensitive allele of Ppd-D1, differences between the winter genotype and genotypes with a spring allele at one of the genes ranged from 3.5 days for Vrn-B1 to 4.9 days for Vrn-D1. Smaller differences occurred between genotypes with a spring allele at one of the Vrn genes and those with spring alleles at two of the three genes. The shortest time to heading occurred for genotypes with spring alleles at both Vrn-A1 and Vrn-D1. Differences between the photoperiod-sensitive and insensitive alleles of Ppd-D1 depended on the genotype of the vernalization genes, being greatest when three spring alleles were present (11.8 days) and least when the only spring allele was at Vrn-B1 (3.7 days). Because of these epistatic interactions, for the practical purposes of using these genes for cross prediction and marker-assisted selection we concluded that using combinations of alleles of genes simultaneously would be preferable to summing effects of individual genes. The spring alleles of the vernalization genes responded differently to the accumulation of vernalizing temperatures, with the common spring allele of Vrn-A1 showing the least response, and the spring allele of Vrn-D1 showing a response that was similar to, but less than, a winter genotype.

The photoperiod sensitivity gene Ppd-D1 and the vernalisation genes Vrn-A1, Vrn-B1, and Vrn-D1 are known to contribute to optimal adaptation to specific environments. Diagnostic molecular markers for detecting important alleles of these genes are now available, including for 2 distinct spring alleles of Vrn-A1 (a and b). As a first step for determining the relative importance of these alleles, they were characterised in Australian cultivars released from the late 19th until the early 21st Century. The photoperiod-insensitive Ppd-D1a allele did not occur in the Australian cultivars we assessed until after the release of cultivars containing CIMMYT germplasm in 1973. Thereafter, this allele became common; however, cultivars with an alternative, presumably photoperiod-sensitive, allele have continued to be released for all parts of the Australian wheatbelt, including for latitudes less than 28°S. In contrast to other parts of the world, Vrn-A1b was frequent in cultivars released during the first 70 years of the 20th Century and is still present in modern cultivars. Before the use of CIMMYT germplasm, the spring allele of Vrn-B1 and the winter allele of Vrn-D1 were common. Four major combinations of alleles of these major genes were identified in modern cultivars: first, those similar to WW15 (Anza), with the Ppd-D1a allele, the spring Vrn-A1a allele, and winter alleles at Vrn-B1 and Vrn-D1; second, those similar to Spear or Kite, with the alternative, photoperiod-sensitive allele at Ppd-D1, the spring Vrn-A1a allele, the spring Vrn-B1a allele, and the winter allele at Vrn-D1; third, those similar to Pavon F 76, with the Ppd-D1a allele, the winter allele at Vrn-A1, and the spring alleles at Vrn-B1 and Vrn-D1; fourthly, those similar to Gabo, with the winter allele at Vrn-A1, the spring allele at Vrn-B1, the winter allele at Vrn-D1, but the Ppd-D1a allele. Other combinations were found, including those for winter cultivars and those for early heading cultivars. A hypothesis was suggested for the facultative cv. Oxley. Evidence was presented to suggest that modern full-season cultivars head ~1 week earlier in a Mallee environment than cultivars from the late 19th Century.

Knowledge of the relative contributions of genotype (G), environment (E), and genotype and environment interaction (G × E) effects on wheat (Triticum aestivum L.) quality leads to more effective selection in breeding programs and segregation of more uniform parcels of grain better suited to the needs of customers. Their effects on wheat quality were reviewed using papers obtained from 4 major international databases. The literature is dominated by research from North America, with lesser contributions from Europe, Australia, and the rest of the world. Use of analysis of variance to partition sources of variation due to G, E, and G × E was the most common approach but, more recently, residual maximum likelihood methods that can accommodate large, but unbalanced, datasets have been used. In North America and Europe, the relative contributions of G, E, and G × E varied across studies, but traits associated with protein content were more influenced by E and G × E than those associated with protein quality, dough rheology and starch characteristics, where G effects were more important. Variation in the relative contributions of G, E, and G × E was highly dependent on the G and E sampled. The Australian studies were characterised by a relative lack of G × E, with G and E rankings being similar across the country for the protein quality, dough rheology, and starch quality traits examined in detail. This suggests that, in Australia, more efficient testing of potential cultivars will be possible for these traits, especially when the underlying variation at the gene level is known, and that efficiencies in the design and conduct of trial systems and quality evaluations could be achieved by testing samples from targetted environments without affecting genetic gain and overall crop quality.

Production of wheat of sufficient quality to meet market demands is an ongoing agricultural challenge. Identification and evaluation of alleles of genes affecting quality parameters enables breeders to improve their germplasm by active selection towards specific allele combinations. Using a large dataset obtained from southern Australian wheat breeding programs, and including a relationship matrix in the analysis to minimise bias, we re-evaluated the effects of high- and low-molecular-weight glutenin alleles and puroindoline alleles on the grain quality parameters Rmax, dough extensibility, dough development time, flour water absorption, and milling yield and found that estimated effects were in close agreement with those from earlier analyses without a relationship matrix. We also evaluated, for the first time, the effects on the same quality parameters of 2 alleles (wild-type and null) of a defence grain protein, a serpin located on chromosome 5B. In addition, we assessed the effect of the VPM1 alien segment. The serpin null allele significantly reduced milling yield by ~0.4 g of flour per 100 g of grain milled across different germplasm sources and flour protein levels. In Australian germplasm, the origin of this allele was traced to a 19th Century introduction from India by William Farrer; however other sources, of significance in international breeding programs, were also identified. Our analysis of the effect of the VPM1 segment on quality traits revealed no detrimental effects of its presence on the traits we measured.

Glutenin genes were known to influence maximum dough resistance (Rmax), dough extensibility (extensibility), and dough development time, whereas puroindoline genes were known to influence grain hardness, flour water absorption (water absorption), and milling yield. These are important determinants of grain quality of wheat in Australia. This study was conducted to investigate the combined effect of these genes on Rmax, extensibility, dough development time, water absorption, and milling yield in a large dataset assembled from the breeding programs based at Horsham, Victoria; Roseworthy, South Australia; and Wagga Wagga, New South Wales; for at least 10 seasons. The effect of the glutenin genes on Rmax, extensibility, and dough development time was confirmed, as was the effect of the puroindoline genes on water absorption and milling yield. In addition, puroindoline genes were shown to significantly affect extensibility and dough development time. The Pina-D1a/Pinb-D1b genotype increased extensibility, dough development time, and milling yield relative to the Pina-D1b/Pinb-D1a genotype. Both of these genotypes are present in cultivars classified as hard-grained in southern Australia. Therefore, the allelic composition of both glutenin and puroindoline genes is required to predict the grain quality of hard wheat in southern Australian breeding programs. The glutenin and puroindoline genes in combination accounted for more than 50% of the genotypic variance for these traits, except for milling yield, but a substantial proportion of the genotypic variation could not be attributed to these genes, indicating that other genes affecting the traits were present in the populations of these wheat-breeding programs.

Determining how to choose parents and conduct selections is a critical issue in plant breeding. The genetic and breeding simulation tool QuCim can predict the outcome of a cross under a specific selection scheme, when genetic information for the targetted traits is known. In this paper, we use genetic information from Australian wheat breeding programs about glutenin, as it relates to wheat quality, to predict the outcomes from some example crosses. The 8 Silverstar sister lines used in our study are morphologically very similar, but have different values for 2 important quality traits, maximum dough resistance (Rmax) and extensibility. Supposing we intend to use Silverstar in crosses with other adapted cultivars, without losing grain quality, which sister line should we use? Under the condition that high Rmax is the major breeding objective, QuCim simulation showed that Silverstar 3 and 7 should be chosen if the other parent does not have allele b at Glu-A3 and allele d at Glu-D1. If the other parent has allele b at Glu-A3 and allele d at Glu-D1, all 8 lines can be used. If the other parent does not have allele b at Glu-A3, but has allele d at Glu-D1, Silverstar 3, 4, 7, and 8 should be used, and if the other parent has allele b at Glu-A3, but does not have allele d at Glu-D1, Silverstar 1, 3, 5, and 7 should be used. Therefore, the optimum Silverstar line depends on the alleles present at glutenin loci in the other parent. Australian wheat cultivars Krichauff and Machete have a similar value for Rmax, but they differ substantially as a donor for improving Rmax in other parents. For crosses with Australian wheat cultivar Trident, Machete is the better choice, but for crosses with the Australian wheat cultivar Westonia, Krichauff is better. In conclusion, QuCim can accurately predict the outcome from a specific cross under a selection scheme when gene information is known. It can help breeders identify the best crosses and selection methods to achieve their breeding objectives.

Grain hardness is a major determinant of the classification and end-use of wheat. Two genes, Pina-D1 and Pinb-D1, have a major effect on this trait, so for wheat breeding programs it is important to identify the alleles of these genes present in elite germplasm. This study was conducted to identify the alleles present in southern Australian germplasm, and to determine if they affected quality characteristics other than grain hardness.Only 3 genotypes were identified. These were Pina-D1a/Pinb-D1a producing soft grain, Pina-D1a/Pinb-D1b producing moderately hard grain, and Pina-D1b/Pinb-D1a producing very hard grain. WW15 was the probable source of Pina-D1a/Pinb-D1b in most cultivars; however, Halberd represented another source. An important source of Pina-D1b/Pinb-D1a was the CIMMYT line Pavon, with sources from the old Australian cultivars Gabo and Falcon probably still present in modern germplasm.In an analysis of grain quality data from the Victorian Institute for Dryland Agriculture breeding program, the Pina-D1b/Pinb-D1a genotype had a significantly higher water absorption and significantly lower milling yield than the Pina-D1a/Pinb-D1b genotype, which indicates that these genes will impede the development of hard-grained cultivars that combine high water absorption and high milling yield.

The effects of genes in self-pollinated crops are usually estimated from designed experiments where selection is minimised. In this study, we used a large, but unbalanced, dataset from a barley breeding program to estimate the effects of the Ha2, Ha4, and sdw1 genes on grain yield, grain weight, grain protein, malt extract, and diastatic power. The Ha2 and Ha4 genes for resistance to cereal cyst nematode were under intense selection pressure, whereas the sdw1 gene, which reduces plant height, was under mild selection pressure.From a mixed-model analysis of mainly F5-derived lines over 5 years, resistance due to the Ha2 gene was found to increase grain yields at 2 sites where the nematode was expected to be present, but not at 3 other sites. There was no significant effect of Ha4 on grain yield. Because of selection, data from later stages of evaluation were not useable for Ha2 or Ha4. From analyses of both early stage and later stages of evaluation, the semi-dwarf allele of the sdw1 gene increased grain yields at high-yielding sites, but decreased yields at low-yielding sites. The semi-dwarf allele reduced grain weight. The effects of Ha2 or Ha4 on malt extract and diastatic power were not significant, but the semi-dwarf allele at sdw1 reduced grain protein.We concluded that plant breeding data can be used to successfully estimate the effects of important genes, with bias due to selection minimised by the use of data from appropriate stages of selection and the use of appropriate statistical models.

Glutenins are the major determinant of dough characteristics in wheat. These proteins are determined by genes at 6 loci, with multiple alleles present in southern Australian breeding programs. Previously, we estimated the effects of these genes on maximum dough resistance (Rmax), dough extensibility and dough development time. Subsequently, the allele previously classified as Glu-B1b was found to consist of 2 alleles, with one, now considered to be Glu-B1al, producing an overexpression of the Bx7 glutenin subunit. Therefore, there is a potential bias in our previous estimates. An extended dataset was analysed with the 2 alleles now separated. These analyses identified negligible biases in our previous estimates, probably due to a low frequency of Glu-B1al before 1999. However, Glu-B1al produced significantly higher Rmax, dough extensibility, and dough development time values than all other alleles at the Glu-B1 locus. Therefore, at intermediate allele frequencies, substantial bias in estimates of the effects of the Glu-B1 alleles can be expected without correct identification of Glu-B1al.

Glutenins are a major determinant of dough characteristics in wheat. These proteins are determined by genes at 6 loci (Glu genes), with multiple alleles present in most breeding programs. This study was conducted to determine whether estimates of allele effects for the important dough rheological characters, maximum dough resistance (Rmax) and dough extensibility, could be determined from aggregated data from southern Australian wheat breeding programs using statistical techniques appropriate for unbalanced data. From a 2-stage analysis of 3226 samples of 1926 cultivars and breeding lines, estimates of Rmax and extensibility effects were obtained, first for the lines, and then for 31 glutenin alleles. Glutenin genes did not determine flour protein concentration, and this character was used as a covariate. Rankings of the estimates of Rmax for the alleles were similar to the relative scores for dough strength reported from previous studies, providing strong evidence that the analysis of a large, unbalanced data set from applied wheat breeding programs can provide reliable estimates. All 2-way interactions between loci were present for 18 of the alleles. Analyses including interactions showed that epistasis was important for both Rmax and extensibility, especially between the Glu-B1 locus coding for high molecular weight glutenins and the Glu-A3 and Glu-B3 loci coding for low molecular weight glutenins. Because of the complexity of these interactions, similar values of Rmax and extensibility were predicted for diverse combinations of alleles. This implied that the practical application of glutenin genes in applied wheat breeding would be greatly enhanced by computer software which can predict dough rheology characteristics from glutenin allele classifications.

An enzyme-linked immunosorbent assay (ELISA) for the discrimination of Wx-B1a and Wx-B1b genotypes at the granule-bound starch synthase I (GBSSI) or waxy locus of hexaploid wheat (Triticum aestivum L.) was adapted to a high-throughput, 96-well microtitre plate format. This test is applicable to the direct analysis of starch, flour, or crushed grain and requires less than 1 grain to perform. Several hundred samples may be routinely analysed in one day. The assay was validated using quantitative trait locus (QTL) analysis of a doubled haploid mapping population of the cross Cranbrook (Wx-B1a)/Halberd (Wx-B1b). This demonstrated that the assay unambiguously identified 153 of 161 lines analysed, with a highly significant QTL (LRS value 270) accounting for 83% of ELISA variation, at the Wx-B1 locus on chromosome 4AL. In addition, measurement of total GBSSI variation using a non-isoform-specific GBSSI detection monoclonal antibody also gave a significant QTL (LRS of 84, accounting for 42% of ELISA variation) at the Wx-B1 locus. Application of the assay to crude flour extracts of 8 grains for each of 1093 progeny from 4 crosses segregating at the Wx-B1 locus permitted the unambiguous scoring of lines as pure Wx-B1a or pure Wx-B1b. The scoring by ELISA was strongly related to the flour swelling volume of the lines, thus demonstrating the utility of this high-throughput screening method for the faster, more efficient development of Australian noodle wheats.

Changes in glutenin, gliadin, glutenin subunit composition, and polymer size distribution were monitored for 4 cultivars of wheat (Triticum aestivum L.) throughout grain filling in an irrigated and non-irrigated environment over 2 seasons. The synthesis of glutenin and gliadin was modelled using a logistic function to determine the rate and duration of synthesis in response to environmental conditions. The maximum rate of synthesis of glutenin occurred approximately 6–8 days after the maximum rate of gliadins, with the duration extended by a similar period. High molecular weight glutenin subunits (HMWGS) were detected earlier than low molecular weight glutenin subunits (LMWGS). After the initial synthesis of HMWGS, there was a period at approximately mid grain filling when the rate of synthesis was reduced, followed by a period of more rapid synthesis in the latter stages of grain filling. In contrast, once detected, LMWGS increased at a faster rate than, and were in excess with respect to, HMWGS. Cultivar and environmental differences were observed, but in all cases the average molecular weight of polymeric glutenin increased throughout grain filling. Large polymers (>400 kD) increased continuously during grain filling, whereas polymers in the range 150–400 kD remained relatively constant and smaller polymers

Data from advanced breeding experiments between 1985 and 1994 were used to determine the effects of region, year and environment on the quality of canola grown across Victoria. Estimates from these unbalanced data were made using residual maximum likelihood. Environmental effects were large relative to cultivar effects for oil and protein content, while the reverse occurred for glucosinolate content. High oil contents (and low seed protein contents) were correlated with cooler spring temperatures and higher spring rainfall. Oil contents were lowest, on average, in canola grown in dry years, or from the hotter regions, such as the Mallee, and were highest in canola from the cooler, wetter regions, such as south-western and north-eastern Victoria. Fatty acid composition varied with year and region. Means for saturated fatty acid content averaged 6.4 0.1%. The oleic acid content averaged 60.3 0.4% and was higher in canola grown in central Victoria and the Wimmera, and in most years, in north-eastern Victoria compared with other regions. Low temperatures and low rainfall reduced oleic acid content. Linoleic acid content averaged 19.7 0.3% and linolenic acid averaged 10.4 0.3%, with the content of these fatty acids negatively correlated with the content of oleic acid. Erucic acid levels were below 0.6% in all regions.

Glutenins and gliadins are the major components of the storage protein in wheat and make a significant contribution to dough rheology and baking quality. Qualitative differences in these proteins are known to be important for dough rheology, particularly for glutenins, but much less is known about quantitative differences, especially as influenced by field environment. Flour protein, the proportion of glutenin and gliadin in flour protein, loaf volume, and the dough rheological characters dough development time, dough breakdown, dough extensibility, and maximum dough resistance (Rmax) were determined for 7 cultivars grown in 15 diverse environments. The proportion of glutenin in flour protein was highly dependent on cultivar, whereas, although cultivar was still important, environmental variation was greater than cultivar variation for gliadin. Environmental variation was greater than cultivar variation for the dough rheological characters. Across environments, the proportion of gliadin increased with increasing flour protein, whereas the proportion of glutenin decreased. An index of accumulated temperatures above 30˚C during the first 14 days after anthesis explained a significant proportion of the increase in gliadin, and, to a lesser extent, the decrease in glutenin. Increasing Rmax and dough development time, and more rapid dough breakdown, were also associated with this index. The rate of increase of Rmax with the temperature index was greater for cultivars with the Glu-D1a allele than those with the Glu-D1d allele, suggesting that the relative performance of cultivars with different alleles at this locus depends on environment.

Most field studies investigating the effect of temperature on growth processes use temperatures recorded within a Stevenson screen. These are likely to deviate from temperatures within the plant. This investigation reports a comparative study of methodologies and applications for measuring temperatures in the field during grain development by comparing Stevenson screen, ambient (air temperatures within the crop canopy), and wheat spike temperatures. Miniature sensors were inserted into wheat spikelets located midway on the spike of a primary tiller at anthesis. Located also within the crop canopy, and at the same height as the spike sensors, were sensors to measure ambient temperatures. Stevenson screen temperatures were also recorded at the site. Temperatures were recorded automatically every 12 min during grain filling from anthesis to maturity. Plants were grown in dryland and irrigated conditions within the same location, with the aim of determining differences in plant temperatures between stressed and non-stressed plants. Stevenson screen temperatures did not relate closely to ambient or spike temperatures. Plants growing in adequate soil moisture conditions had spike temperatures lower than ambient temperatures, but in some dryland trials, where soil moisture was limiting, spike temperatures equalled ambient temperatures, indicating that the plants were under moisture stress. Temperature differences of up to 5˚C were observed between the spikes of irrigated and non-irrigated crops on a hot day. Neither ambient nor screen temperatures gave an accurate measurement of spike temperature on hot days. Spike temperature differences between 2 cultivars, awned and awnless, were investigated. Trends were not consistent over both years; however, in 3 of the 4 environments, the maximum spike temperatures were higher for the awned cultivar (Hartog) than the awnless cultivar (Halberd). On very hot days, when ambient temperatures exceeded 40˚C, spikes of Hartog were cooler than those of Halberd.

In Australia, the period during grain filling for wheat (Triticum aestivum L.) is often associated with increasing ambient temperatures and diminishing soil moisture conditions. This can affect grain size and grain protein concentration. In this study, grain filling and nitrogen accumulation were investigated by sampling every 7 days during grain filling for 4 cultivars: Rosella, Hartog, Halberd, and Eradu. The plants were grown in trials with and without irrigation in 1991 and 1992, which were seasons with divergent temperatures and rainfall during this period. A4-term logistic function, using both days after anthesis (DAA) and growing degree days (GDD), was fitted to data to estimate maximum rate and duration of grain filling. The logistic model proved to be, in most cases, an accurate method to determine the rate and duration of grain filling and nitrogen accumulation. Probably because of differences in availability of soil moisture, the use of GDD did not improve on the estimates obtained from using DAAas the independent variable. In 1991, a relatively dry year, non-irrigated plants showed signs of wilting. In that year, grain nitrogen contents on a per grain basis were similar in both the irrigated and non-irrigated (dryland) environments, but grain weights were much higher from the irrigated environment. The maximum rate and duration of grain filling were lower in the dryland environment. In contrast, whereas the duration of nitrogen accumulation was similarly shorter in the dryland environment, the maximum rate of accumulation was substantially higher. In 1992, a cooler and wetter year, differences between irrigated and non-irrigated environments were smaller, but the trends for rate and duration were similar. We concluded that, under stress conditions, higher rates of accumulation of grain nitrogen and lower rates of accumulation of carbohydrate, rather than differences in duration of accumulation, were primarily responsible for increased grain nitrogen concentrations. In general, cultivars used in this study were ranked similarly for rate and duration of grain filling across environments, with the exception of Hartog, which had a significantly lower maximum rate in the dryland treatment in 1991. This suggests that Hartog may be more sensitive to drier conditions than the other cultivars. In almost all environments, Eradu had a higher maximum rate of accumulation of grain nitrogen than other cultivars; however, the duration was reduced, so that in the mature grain, grain nitrogen concentration was not significantly different.

The composition of starch in wheat is an important determinant of grain quality, especially for white-salted noodles. Starch consists of 2 types of polymer, amylose and amylopectin, and occurs in predominantly larger A-type and smaller B-type granules. High starch pasting peak viscosity is desirable for white-salted noodles, and is influenced by the waxy genes coding for granule-bound-starch synthase (GBSS), which are involved in the synthesis of amylose. To study cultivar and environmental effects on the proportion of A-type granules, the proportion of amylose in starch, starch pasting peak viscosity, and grain hardness, 7 cultivars were grown in 15 environments which differed for temperature during grain filling. These cultivars varied in grain hardness classification and for the presence of GBSS coded by the Wx-B1 locus. Cultivars null for Wx-B1 GBSS had higher pasting viscosity than those with Wx-B1 GBSS, verifying the null requirement for cultivars suitable for white-salted noodles. However, the relationship between amylose concentration and pasting viscosity was complex, indicating that Wx-B1 influences pasting viscosity beyond its influence on the proportion of amylose and amylopectin. Environments with a high level of accumulated temperatures above 30ºC during the first 14 days after anthesis produced grain with a high proportion of A-type granules, even when irrigated. The proportion of amylose also increased with increasing accumulation of temperatures above 30ºC during the first 14 days, but was not influenced by temperature to the same extent as granule type. Environmental variation in pasting peak viscosity was large, but not related to high temperature. The hardness of grain was related to accumulated temperatures above 30ºC during the second 14 days after anthesis, with the increase in hardness much greater in soft-grained than hard-grained cultivars.

Starch quality, particularly high paste viscosity, is important in producing marketable wheat for several end uses. Peak starch paste viscosity was measured for 65 wheat cultivars significant to Victorian wheat breeding. Coefficients of kinship were calculated between these cultivars to assess their genetic relationships. In terms of paste viscosity, 15 of the 20 highest ranking cultivars were related. Currawa, a cultivar released in 1912, was the common ancestor and proposed source of high paste viscosity in this family of cultivars, which included the currently grown cultivar, Rosella. Most cultivars in the lower rank were closely related to WW15, which is a semi-dwarf parent from CIMMYT that was used extensively in Australian breeding programs in the past two decades. This survey provides information for choosing parental material for starch quality improvement and offers an explanation for the decrease in peak viscosity of modern Australian cultivars.

Improvements in malting quality are important if barley from south-eastern Australia is to remain competitive on export markets. Grain is desired that will produce high levels of malt extract and diastatic power but has moderate levels of grain protein. To examine cultivar and environmental effects, especially nitrogen (N) fertilizer, on levels of malting quality parameters and their correlations, seven cultivars of barley were grown in a fallow and pea stubble rotation with five levels of N fertilizer in the Wimmera region of Victoria in 1990 and 1991. The first season was relatively dry and warm, while the second was wetter and cooler. Grain yield and malt extract were markedly lower in 1990 than 1991, and grain protein concentration, grain screenings and diastatic power were significantly higher. Grain protein and diastatic power increased almost linearly with increasing N application, with a higher rate of increase in 1990 than in 1991. Malt extract declined almost linearly with increasing N application, but the change in rate of decline between seasons was less than the change of rate of increase of grain protein. Environmental correlations between protein concentration and malt extract, and between malt extract and diastatic power, were negative. They were close to -1.0 when the environmental factor varying was restricted to N fertilizer, but were of a smaller absolute magnitude when seasons and rotations were also allowed to vary. In contrast, genotypic correlations were of intermediate magnitude. Broad-sense heritabilities for malt extract and diastatic power were relatively high, even with such contrasting seasons. This indicates that it should be possible to develop cultivars for south-eastern Australia which have high malt extract and high diastatic power at low protein levels. However, applications of N fertilizer that raise grain protein concentration will reduce malt extract, with the effect much greater in drier, warmer seasons.

The early history of maize (Zea mays L.) in New Zealand is reviewed and we concluded that maize was probably first introduced in 1772. By 1819 the crop was definitely being grown by Maori agriculturalists and it has almost certainly been grown continuously since that time. To elucidate the genetic origins of New Zealand maize, 5 open-pollinated varieties for which viable seed was still available were grown and described. These varieties were Marigold, Motiti, a Maori selection, a Maori sweetcorn, and Horsetooth. Marigold was similar to the Cateto flints from eastern South America or the Mediterranean region; the Maori sweetcorn was similar to the Black Mexican sweetcorns of New York State, USA; and Horsetooth was similar to the Hickory King complex from southern USA. Motiti and the Maori selection probably originated in New Zealand by cross-pollination between undetermined dent and flint varieties. We concluded that several distinct races of maize have been introduced into New Zealand and unique ...

Full-sib, paternal half-sib, and S1 families derived from a tropical highland population of maize (Zea mays L.) were used to study genetic variability for time to coleoptile emergence, shoot weight, leaf number, and visual assessment of chlorophyll concentration at 24 days in a 15°c day/10°c night environment. Considerable genetic variation occurred for time to emergence, shoot weight, and leaf number. Part of the variation for shoot weight and leaf number could be attributed to initial seed weight, especially for shoot weight, but substantial variation occurred which was independent of seed weight but was related to time to emergence. Inbreeding depression of substantial magnitude occurred for time to emergence, shoot weight, leaf number, and chlorophyll concentration. The use of selected families from this population for the improvement of time to emergence, and hence early seedling growth, of maize cultivars under cool conditions was discussed.

Full-sib, paternal half-sib and S1 families were derived from a population of maize, Pool 5, with a wide germplasm base. These families were used to study genetic variation for germination percentage, emergence percentage and time to emergence at 10°C.

Four cultivars of oats (Avena sativa L.) (Amuri, Avon, Florida 501, and Florida AB113) were grown during winter in the Manawatu for 3 years to measure cultivar, year, cultivar x year interaction, and harvest date effects on forage quantity and quality. The quantity of forage produced at a given harvest date was dependent on cultivar and temperatures preceding that harvest date. Cultivar x year interactions were not important. The quality of all cultivars, in terms of digestibility and nitrogen concentration, was reasonably satisfactory for animal production until flag leaf emergence began in August or September. After that, the digestibility declined rapidly from 80% to 55%. The nitrogen concentrations declined steadily throughout the winter from 4.5% to near 1%.

The improvement of rate of seedling emergence and early seedling growth of maize (Zea mays L.) under cool conditions has been an objective of breeding programs in cool regions for many years. To study inheritance of emergence time, and to determine if differences in emergence time were due to differences in seedling growth, F1, F2 and backcross generations of a diallel cross of two rapidly emerging lines from CIMMYT Pool 5, 5-113 and 5-154, and two elite Corn Belt Dent lines, A619 and A632, were grown in controlled environment rooms at low temperatures.The lines from Pool 5 emerged significantly faster than A619 and A632 over a range of low temperature conditions. This difference occurred both when the lines themselves were tested and when the lines were tested as male and female parents in crosses. The Pool 5 lines converted a higher proportion of their original seed to new root and shoot tissue than did A619 and A632, indicating that they had a faster seedling growth rate. Primarily this was due to a faster loss of seed reserve, rather than a more efficient conversion process.A significant difference occurred between A619 and A632 for emergence time, but this was not due to a difference in seedling growth rate.Reciprocal differences occurred only in the F1 generation in crosses involving A619, and then marked effects could be attributed to the male parent. Reciprocal differences tended to disappear in the F2. This suggested that the genotype of the embryo and endosperm was of much greater importance than the genotype of the maternal parent in determining differences of time to emergence and seedling growth.Mid-parent heterosis occurred for time to emergence and seed loss, a measure of mean rate of utilization of seed reserve, in all crosses. High parent heterosis occurred in several crosses for these traits. High parent heterosis occurred in all crosses for efficiency of utilization of seed reserve.A generation means analysis indicated that both additive and dominance effects were present for rate of seedling growth in crosses between A632 and the Pool 5 lines.

Two Libyan strains of Avena sterilis L. and two cultivars of A. sativa L. were grown at three levels of available nitrogen and at two temperatures in controlled-environment rooms. The strains of A. sterilis produced groats with protein concentrations significantly greater than those of the cultivars of A. sativa under all nitrogen and temperature conditions. One strain produced straw with a greater nitrogen concentration, but because of a low harvest index, it did not have a higher concentration of nitrogen in the entire shoot. The other strain appeared to synthesise groat protein faster than the A. sativa cultivars during the early stage of grain development and was considered to have potential as a donor of genes for the improvement of protein content in cultivated oats. Both strains of A. sterilis had shorter grain-filling periods than the cultivars of A. sativa.

Testcrosses between 37 SI plants of Pool 5 (a high altitude tropical population of maize) and 2 single-cross testers of Corn Belt Dent origin were produced at Palmers ton North. Check hybrids were produced by crossing 4 inbred lines to the same testers. Pool 5 testcrosses produced similar grain yields to the hybrid checks, in both Palmerston North's cool environment and the warmer environment of Gisborne. Silking dates and grain moisture percentages were similar to those of the hybrids, indicating that this highland tropical population is reasonably well adapted to the temperate New Zealand environment. One Pool 5 testcross produced higher yields than any of the hybrid checks at both sites. Seedlings of the testcrosses of Pool 5 lines generally emerged and grey faster autotrophically than the check hybrids in cool controlled-environment rooms. They were also greener and apparently more chilling-tolerant. However, the seedling measurements of adaptation to these cool conditions were not correlated...