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Powdery mildew significantly hampers pea yield and deteriorate its quality as well. The resistance breakdown remained the main reason for failure in each attempt to incorporate powdery mildew resistance in well adapted pea cultivars. A precise selection of powdery mildew resistant source is the key to develop high yielding and stable powdery mildew resistant cultivars. Field screening alone is not an efficient method for making selection for powdery mildew resistance. Different physiological parameters viz., the concentration of total chlorophyll, chlorophyll b, chlorophyll a: chlorophyll b and the number of stomata were found to be in a tight positive correlation with disease severity while, the concentration of chlorophyll a had negative correlation. The differential behaviour of these traits in powdery mildew susceptible and resistant genotypes has suggested their use as reliable criteria for screening against powdery mildew. A 1-5 scale has been devised for screening against powdery mildew in pea; where score 1 is for highly resistant and 5 for highly susceptible genotype. The suggested scale is reliable and reproducible in making selections for powdery mildew resistance. [ABSTRACT FROM AUTHOR]

Okra (Abelmoschus esculentusMoench) is valued for its edible green seed pods. Twenty-five okra genotypes were sown to determine the genetic variability for 10 yield- and quality-related traits. Minor differences between genotypic and phenotypic variance indicated low environmental variance. All traits were positively correlated with yield per plant except for photosynthetic-active radiation and carbohydrate percentage, which exhibited a negative association. Cluster analysis grouped genotypes in three clusters; cluster 1 consisted of five genotypes; cluster 2 consisted of 13, and cluster 3 consisted of seven. The three principal components explained 63.5% of total existing genetic variability. Selection from genotypes in cluster 1 had high genetic diversity, which results in high pod yield. The genotype Diksha could be used for developing plants with good quality fruit. [ABSTRACT FROM AUTHOR]

Garlic (Allium sativumL.) is the second most important bulb crop. To understand the genetic association and genetic variability between yield and its related traits among garlic genotypes, three garlic clones and a check were planted according to randomized complete block design. The elite garlic clone Wv had the highest garlic bulb yield over all entries. Yield is a complex quantitative trait associated with different plant traits. Garlic bulb yield was associated with plant biomass, bulb diameter, number of bulbs, and number of cloves. The plant traits leaf area, number of leaves, and plant height had minor effects on bulb yield. Principal component analysis reduced the original eight quantitative characters to three principal components that explained 100% of variation among four accessions of garlic. The proportions of the total variance attributable to the first three principal components were 60.8%, 25.4%, and 13.4%. ‘Wv’ and ‘Wn’ belong to the first cluster that has diversity for plant height, leaf area, and bulb yield, whereas ‘Lahsan Gulabi’ has diversity for bulb diameter and number of bulbs per square meter. Careful selection among these clones could be effective in improving garlic. [ABSTRACT FROM PUBLISHER]

The genetic resistance in high yielding pea cultivars against powdery mildew provides a cost effective and reliable strategy to reduce the yield losses and save quality of the harvest. The dependable selection of powdery mildew resistant source(s) is the most crucial step in breeding for disease resistance. The efficiency of a simple, reliable and reproducible screening method on detached leaves of pea under controlled environmental condition was evaluated in comparison with field screening under natural conditions. The detached leaf assay coupled with microscopic quantification of susceptibility percentage (%S) appeared ten times more precise and reproducible than field screening based on visual observation of percentage of leaf area affected with disease. A new 0-5 microscopic disease scale proposed here is more robust and stringent for making selections for powdery mildew resistant parents and effectively challenging the segregating populations against different isolates of Erysiphe pisi simultaneously. The disease scale is based on susceptibility percentage (%S) as a function of percentage of germinated conidia with mycelial growth. For making more precise calculations non germinated conidia without germ tube were not taken in to account. The use of detached leaf assay and microscopic quantification of conidia has provided a simple and reliable screening method to clearly distinguish between escape and resistance mechanisms and the results are not prone to fluctuations in environmental conditions. The assay results were highly correlated (0.993) with the disease severity of whole plants under field conditions; moreover, dCAPS markers have also validated the assay results. Two pea genotypes (It-96 and No. 267) have been selected as highly resistant to powdery mildew, which could be used as a source for breeding disease resistant pea cultivars. [ABSTRACT FROM AUTHOR]

The incidence of powdery mildew disease on pea (Pisum sativum L.) is a major limiting factor to maximizing yields in different ecological and geographical zones due to environmental factors and the presence of pathogenic variation in Erysiphe polygoni DC. In order to develop a widely adopted powdery mildew–resistant cultivar it is necessary to challenge genotypes with all available pathogenic variants. In order to examine pathogenic variation, 23 naturally occurring single colony isolates of E. polygoni, collected from geographically diverse locations, were subjected to pathogenicity testing and characterization using a detached leaf assay. Isolates demonstrated small differences in pathogenicity against pea. Isolates MUZ-1 and MUZ-2 were the most virulent and produced disease symptoms even on the resistant cultivars. Isolates TTS-2 and TTS-6 were less virulent. Significant variation occurred among isolates for quantitative and qualitative parameters regardless of the degree of pathogenicity. There was variation for conidium length, conidium width, cleistothecia number, number of hyphae, ascus number, ascus length, ascospore number, and ascospore width. An unweighted pair group method with arithmetic mean phenogram, constructed on the basis of quantitative parameters, indicated that isolates were morphologically different but pathogenicity was not controlled by morphological features of the isolates, though morphological features can be used to distinguish between isolates. [ABSTRACT FROM PUBLISHER]

Powdery mildew disease caused by Erysiphe polygoni DC significantly reduces yield quantity and quality of edible seed in pea (Pisum sativum L.). Development of powdery mildew–resistant varieties is an economical and environmentally friendly approach to managing the disease. One hundred forty-six pea accessions, collected from different countries, were screened against powdery mildew. It was determined that accessions 9057, 9370, 9375, 10609, 10612, 18293, 18412, 19598, 19611, 19616, 19727, 19750, 19782, 20126, 20152, 20171, It-96, No. 267, and No. 380 were resistant; accessions It-96 and No. 267 were highly resistant. The correlation between disease score and latent period was negative, suggesting that these parameters should be used simultaneously for more precise screening against powdery mildew. The resistant accessions selected might be used as powdery mildew–resistant parent(s) in breeding programs depending upon the nature and number of gene(s) controlling for resistance. [ABSTRACT FROM AUTHOR]

Effect of honeybee and blowfly pollination on onion (Allium cepa L.) seed production was studied at National Agricultural Research Centre, Islamabad. Pakistan during 2005-06. The experiment was laid out in a randomized complete block design with three treatments (caged plants with honeybee, caged plants with blow flies and caged plants without pollinators-control) and four replications each. Number of seed sets from 10 umbels, one from each replication were counted and weighed. The number of seed sets in caged plants with honeybees was maximum as compared to plants caged with blow flies and control. The same treatment also produced maximum seed weight as compared to other treatments. The results revealed that onion seed setting is dependent on insect pollination. The percentage of seed set for first treatment i.e. the plants caged with honeybees ranged from 62-93 with mean number of 80.7+0.93 (mean + SE), followed by caged plants with blow flies 51-91%, 72.16 + 1.31 (mean + SE)] and control [7-26%, 16.4 + 4.09 (mean + SE)]. The mean weight of seed produced from the plants caged with honeybees was higher (1.90 + 0.11 g) as compared to blow flies caged plants (1.55 + 0.89) and control (0.33 + 0.22). The weight analyses were significantly different in all treatments. It is concluded that honeybees visitation to the flowers is important for pollination but blow flies can be used as an alternate pollinator when honeybees are not available. However, blow flies are not feasible in commercial seed production due to high temperature during peak flowering season in seed production area whereas honeybees are feasible as they can thrive temperature over 40°C. Blow flies are equally good candidates for experimental purposes for pollination. [ABSTRACT FROM AUTHOR]

A study was conducted at Vegetables Research Institute, AARI, Faisalabad, Faisalabad during the year 2011-12 to evaluate the genetic inconsistency and character relationship of ten normal season pea accessions (Climax, FS-2187, Pea-09. 9800-10, GRW-45, KQP-5180, Winner, Green Arrow, Ambassador and 6173). The trial was sown in triplicate randomized complete block design. Data were recorded for days to 50 percent flowering, 100-seed weight, yield per plot, plant height, pods per plant, pod length, seeds per pod and pod width. The data were subjected to analysis of variances using the Statistix 8.1. The results revealed significant differences for all traits studied. Maximum genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) was shown by yield per plot (29.26% and 40.34%) against minimum by plant height (8.78 and 10.15). The broad sense heritability ranged from 54 percent for yield per plot to 99 percent for days to 50 percent flowering. Genetic advance varied from 13.30 percent for plant height to 45.05 percent for 100-seed weight. Correlation coefficient analysis showed positive and significant association among yield per plot, plant height and number of seeds per pod while pod width was highly significantly and positively associated with 100-seed weight. It is concluded that these attributes worked as selection criteria for the development of high yielding lines for normal season of plantation in Punjab. [ABSTRACT FROM AUTHOR]

Adaptability of five exotic varieties of cucumber (Cucumis sativus L.) viz. CU- 2833, CU-5555, GR-102, CFMC-0036, CFMC-0031 was tested under tunnels at Vegetable Research Institute, AARI, Faisalabad, Pakistan during 2012. These exotic lines were compared with locally developed line "Kheera Local" during autumn 2012. Differences of mean yield and number of fruits were found significant among six varieties while emergence percentage was found nonsignificant. The results concluded that plastic tunnels gave early and more production. Exotic varieties produced early fruiting and gave more returns. However, CU-2833 and CU-5555 topped the list with 35.5 and 33.9 tons per hectare, respectively. Locally developed variety "Kheera Local" excelled all these varieties with 48.7 tons per hectare yield. This line also proved to be suitable for prolonged availability of cucumber fruit because it tolerated more temperature as compared with exotic varieties. [ABSTRACT FROM AUTHOR]

BARS-09 is a semi dwarf, rust resistant, drought tolerant and high yielding wheat variety developed as a result of consistent breeding efforts from the year 1999-2007 at Barani Agricultural Research Station (BARS), Fatehjang, Pakistan. The variety was developed from the cross "PFAU/SERI//BOW" and selected from the 16th Semi Arid Wheat Screening Nursery. The genotype was evaluated in multiple trials (preliminary, adaptation, station and regular) from 1999-2000 to 2002-03 under the varietal code 99FJ03. It was further tested in micro yield trial (rainfed) conducted at seven locations in Punjab during 2003-04. The line was also evaluated in National Uniform Yield Trial (rainfed) for two consecutive years 2005 to 2007. It stood third in National Uniform Yield Trials (2006-07) conducted both in Punjab and Pakistan. BARS-09 has shown yield potential of 5613 kg per hectare at Barani Agricultural Research Institute, Chakwal during 2006-07. This variety was approved by Punjab Seed Council during the year 2009 for general cultivation in rainfed areas. BARS-09 is shorter in height (95-98 cm), takes 160-175 days to mature, medium in ear size, has high tillering capacity (480/cm2) and 41.17 g 1000-grain weight. The variety performs better at seed rate of 100 kg and NPK dose of 90-60-30 kg per hectare. It has also shown tolerance against drought and leaf/yellow and stem rusts. It would be a good choice to boost up the wheat production particularly in barani areas of the Punjab. [ABSTRACT FROM AUTHOR]