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Estimates of combining ability help determine the value of hull-less pumpkin (Cucurbita pepo L. var. styriaca) lines in producing new hybrids with high yield and better quality. This research was conducted to estimate the general and specific combining abilities and heterosis in six inbred lines proposed for hull-less pumpkins at the University of Guilan. Analysis of variance indicated that responses for all traits differed significantly. The highest fruit yield and seed length were related to the hybrid 14x16, the highest number of seeds was related to the hybrid 16x23, the highest percentage of oil was related to the hybrid 11x14 and the highest yield of oil was related to 11x23. Considering the high value of combining ability and the heterosis compared to the average of the parent and high parent, it is possible to increase the oil yield and the seed yield by using the 11x23 hybrid. The 16x23 hybrid proposes to increase the number of seeds. The best specific combining ability (SCA) for seed number was associated with the 16x23. The 11x14 had the best SCA for the oil yield per hectare. The 11x 23 had the best SCA for the seed yield per hectare. Significant specific combining ability and high heterosis for traits indicated low additive and high dominant gene action on hull-less pumpkin traits, therefore crossing between lines to release new hybrid cultivars is necessary for Iran's pumpkin breeding program. [ABSTRACT FROM AUTHOR]

SUMMARY: Hybrid breeding is a promising strategy to quickly improve wheat yield and stability. Due to the usefulness of the Rht 'Green Revolution' dwarfing alleles, it is important to gain a better understanding of their impact on traits related to hybrid development. Traits associated with cross‐pollination efficiency were studied using Near Isogenic Lines carrying the different sets of alleles in Rht genes: Rht1 (semi‐dwarf), Rht2 (semi‐dwarf), Rht1 + 2 (dwarf), Rht3 (extreme dwarf), Rht2 + 3 (extreme dwarf), and rht (tall) during four growing seasons. Results showed that the extreme dwarfing alleles Rht2 + 3, Rht3, and Rht1 + 2 presented the greatest effects in all the traits analyzed. Plant height showed reductions up to 64% (Rht2 + 3) compared to rht. Decreases up to 20.2% in anther length and 33% in filament length (Rht2 + 3) were observed. Anthers extrusion decreased from 40% (rht) to 20% (Rht1 and Rht2), 11% (Rht3), 8.3% (Rht1 + 2), and 6.5% (Rht2 + 3). Positive correlations were detected between plant height and anther extrusion, anther, and anther filament lengths, suggesting the negative effect of dwarfing alleles. Moreover, the magnitude of these negative impacts depends on the combination of the alleles: Rht2 + 3 > Rht3/Rht1 + 2 > Rht2/Rht1 > rht (tall). Reductions were consistent across genotypes and environments with interactions due to magnitude effects. Our results indicate that Rht alleles are involved in multiple traits of interest for hybrid wheat production and the need to select alternative sources for reduced height/lodging resistance for hybrid breeding programs. Significance Statement: Hybrid wheat is a promising strategy to increase grain yield. The negative effect on floral traits with relevance for hybrid breeding of different Rht genes using near‐isogenic lines was reported. [ABSTRACT FROM AUTHOR]

Pakistan has a land-based economy that is heavily dependent on farming. It provides 29% of GDP. Put 55% of the labor force to work while supporting 70% of the population in some capacity. The export of agricultural raw materials and completed products produced by agro-based industries accounts for 80% of the country's GDP. Rangelands cover roughly half of the nation's land area. Punjab is well irrigated province of Pakistan. The study on socio economic conditions of Farmers in said district was under taken with prime objective to focus on existing position of Farmers in the field of agriculture. Many socioeconomic, institutional and biophysical factors are causing high wheat yield variation among wheat growers in the country in general and in the Punjab province in specific. Study was conducted in the different divisions of the Punjab. A sample of 737 respondents was selected conveniently. Pre- tested interview schedule was used to collect the information. An unpaired ttest was used to test the differences in the socioeconomic factors and farm sizes on the wheat production. Findings reported that majority of the farmer used traditional method and facing difficulties in the adaptation of hybrid seed and technology due to different socio-economic constraints. In conclusion report also highlights the factors affecting the technological intervention in the farming system. It also specifies the role of gender in the agriculture. By addressing these influences all the stakeholders can make more informed and timely decisions for the development of agriculture sector. [ABSTRACT FROM AUTHOR]

Seed commerce is a highly profitable global market. Most commercialized seeds are hybrid seeds originating from a controlled cross between two selected parental lines. The market value of hybrid seeds depends on their hybrid genetic purity. DNA molecular markers are a reliable and widespread tool to genotype plant materials; however, DNA extraction from seeds is challenging, often laborious and expensive. With the ultimate goal of creating a tomato and melon hybrid seeds purity test, various challenges arise. To overcome these problems and with the purpose of crude DNA extraction, a simple, fast, inexpensive and easily scalable adaptation of the hot sodium hydroxide and tris method coupled to a competitive allele-specific PCR genotyping method is proposed.

Cytoplasmic male sterility (CMS) is a plant's inability to reproduce fertile pollen due to nuclear and mitochondrial genomic incompatibility. In CMS plants, pollen production is disrupted, but this can be restored by nuclear fertility (Rf) genes, while the function of the female organ is typically unaffected. CMS has been intensively used for F1 seed production in self-pollinating crops and practical applications in plant breeding. This comprehensive review explores the intricate mechanisms, applications, limitations, advancements, and prospects of CMS in an agricultural context. Despite its notable advantages, CMS does present limitations, such as instability and genetic vulnerabilities, which are discussed alongside strategies for mitigation. Moreover, the review elucidates on the recent advancements in biotechnology, omics technologies, and breeding approaches, which promise to further harness the potential of CMS in addressing global food security challenges. From the identification of diverse CMS sources to the utilization of advanced genetic engineering techniques like CRISPR-Cas gene editing, the future of CMS in crop breeding appears promising. Thus, the development of diverse sources of CMS and its practical application in breeding are expected in the future. [ABSTRACT FROM AUTHOR]

Chemical fertilizers have been for a long time similar to the original ones created in the 1960's, only recently with the increase emphasis on environmental impact, and the need to reduce quantities of fertilizers used, we have seen the introduction of slow-release and controlled release fertilizers from small surface high value crops towards large field crop production. Side-dressing N fertilizers in maize crops has been a standard in Europe for more than 50 years and thus still has a wide rate of adoption in farms, as it has been the easiest option to apply nitrogen closer to the maximum consumption point, which starts after the plant reaches 8 leaves stage (BBCH-18). Thus, our research has focused on studying the impact of using different rates of nitrogen (40, 80 and 120 kg/ha) of the new release types of fertilizers (Urea NG, Multicote 34-0-7) side-dressing and to establish if there is any benefit, in hybrid seed maize production, of substituting classical fertilizers (ammonium nitrate) with newer ones. The study has been conducted for 3 years in irrigated field research plots in the soil and climatic conditions from north-east of Romania. Our research has revealed several key aspects in terms of the effect on vegetative and generative development of hybrid seed maize plants: longer vegetation period for plants fertilized with slow and controlled release fertilizers, better use of the nitrogen from classical fertilizers as their availability for uptake overlaps with the needs of the plant starting from the side-dress moment. Other aspects evidentiated are reduction in quantity of fertilizer needed, thus economic benefits and similar yield with classical nitrogen fertilizer dressing. [ABSTRACT FROM AUTHOR]

Maize is one of the most widely cultivated crops across the world due to its high importance in animal feeding, human nutrition, and many industrial processes. Fertilization is a key component of any crop production system and it is one of the technological elements where improvement is always searched. Foliar fertilization is an effective way to treat nutrient deficiency, to improve plant nutrition status and to help plants surpass stress periods. Foliar biostimulators are important for giving the possibility to stimulate plant metabolism and enhance plant protection mechanisms. Starting from these ideas, the aim of this paper is to present the results of the research focused on studying the effect of different combinations of classic macro & micro nutrient foliar fertilizers (Basfoliar 36 Extra, Foliar Extra, Vertex Hi-N 34, Maize Extra, Manzinc SC), or of one classic foliar fertilizer combined with one algae based biostimulator (Seamaxx SL) under different base fertilization conditions in irrigated hybrid seed maize production. The research has been conducted for 3 years in irrigated field plots in the pedo-climatic conditions of NE Romania. The obtained results brought to attention the positive effects of foliar fertilizers in hybrid seed production: increased plant height, better foliage development, better tassel development in terms of size and longer pollen shedding time, and finally a yield enhancement. [ABSTRACT FROM AUTHOR]

Quality vegetable seed has the potential to significantly impact nutrition security in sub-Saharan Africa, as the region has the world's lowest per capita production and consumption of vegetables. Moreover, seed companies might have an important role to play, as in Asia, vegetable production and consumption increased rapidly following the expansion of the private seed sector. However, market-driven seed sector development remains contentious, with some celebrating technological advancements and others raising concerns. This paper contributes to seed systems literature by focusing on the role of vegetable crops and diversity within the private sector. It explores the heterogeneous character of the private sector by studying how different business models of leading vegetable seed companies jointly contribute to sector development in sub-Saharan Africa. Eighteen in-depth interviews were conducted with leading vegetable seed companies operating in the region. Qualitative tools were selected to translate individual company data into general findings; while thematic analysis was used to pinpoint a private sector perspective and ideal-type analysis was used to construct business model typologies. The results show that seed companies collectively view seed sector development as a linear trajectory involving public and private investments to enable farmers to adopt increasingly advanced seed types, especially hybrids. In this trajectory, different companies take on different roles based on specialization in seed system functions: variety development, seed production, seed dissemination, and seed use. The coexistence of and collaboration between different (private) actors in the vegetable seed sector contribute to plurality and interaction in line with an integrated approach to seed sector development. However, it is not a static condition as company roles evolve with expanding business models in terms of seed system functions and market segments. A general objective of (national) seed policies is to increase farmers' access and choice in terms of quality seed of improved varieties. Seed sector development interventions can enhance inclusivity by focusing on viable and innovative business models for niche markets in terms of farming systems and crop types. [Display omitted] • Vegetable seed companies foresee a trajectory in which farmers adopt increasingly technologically advanced seed types. • Seed companies play complementary roles in this trajectory prioritizing different seed system functions or market segments. • Public and private investments are being made to support seed sector development with private actors focusing on hybrids. • Hybrid transitions in vegetable crops are being witnessed and anticipated by seed companies across sub-Saharan Africa. • Seed sector development interventions can enhance inclusivity by focusing on viable business models for niche markets. [ABSTRACT FROM AUTHOR]

Hybrid seed production often relies on managed pollinators whose use in isolation cages can pose challenges. Here, we evaluated the pollination ability of the novel managed pollinator Eristalinus aeneus (Diptera: Syrphidae) in hybrid celery and fennel seed crops. During trials performed in 2019–2020 in Cordoba, Spain, we compared seed production with hoverflies released at high and low densities (40–20 ind./m2), and without released pollinators. In celery, we included a treatment with Lucilia sericata (Diptera: Calliphoridae), a blowfly used for seed production (375 ind./m2). The production of celery seeds when E. aeneus were released at high density was significantly higher (+49%) than without released pollinators, for both sterile and fertile plant genotypes; no significant differences were found between the two hoverfly densities and the blowfly treatments. In fennel, seed yield of fertile plants with high density of hoverflies was higher than with low density (+149%), or without released pollinators (+168%); whereas for sterile plants no differences were found between treatments. In both crops and plant genotypes, the highest pollen adhesion to stigmas (number of pollen grains and proportion of flowers with pollen adhered in two stigmas) was obtained with hoverflies at high density. In celery, pollen adhesion was higher with high density of hoverflies than with blowflies for both plant genotypes, despite the considerably lower numbers of released hoverflies. Our results suggest that E. aeneus is a more efficient pollinator of celery than L. sericata, and that it has the potential to effectively pollinate other hybrid Apiaceae seed crops like fennel. [ABSTRACT FROM AUTHOR]

Where maize plays a critical role in food security, governments and donors have invested heavily in support of local, privately owned, often small and medium sized, maize seed enterprises (maize SMEs). Underpinning these investments are strong assumptions about maize SMEs' capacity to produce and distribute seed to smallholders. This study assesses the capacities of 22 maize SMEs in Mexico that engaged with MasAgro—a large-scale development program initiated in 2011 that has provided maize SMEs with improved genetic material and technical assistance. Data were collected onsite from in-depth interviews with enterprise owners and managers and complemented with other primary and secondary sources. Overall, maize SMEs showed high levels of absorptive capacity for seed production, but limited signs of learning and innovation in terms of business organization and strategic seed marketing. Asset endowments varied widely among the SMEs, but generally they were lowest among the smaller enterprises, and access to business development services beyond MasAgro was practically nonexistent. Results highlighted the critical role of MasAgro in reinvigorating the portfolios of seeds produced by maize SMEs, as well as the challenges ahead for maize SMEs to scale the new technologies in a competitive market that has long been dominated by multinational seed enterprises. Among these challenges were limited investment in seed marketing, weak infrastructure for seed production, and limited experience in business management. Achieving the food security goals through maize SMEs will require making national maize seed industry development a strategic imperative. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of hybrid genotypes is a good alternative for increasing the flooded rice yield. However, there is a need for validation of the fertilizer management under different edaphoclimatic conditions and its greater profitability. This study aimed to evaluate the grain yield and profitability of rice hybrids in relation to N doses and fertilization with P and K. Five hybrid cultivars and the conventional IRGA 424 CL cultivar combined with four N doses (0, 100, 150 and 200 kg ha-1) were evaluated, all with fixed doses of 90 kg ha-1 of P2O5 and 150 kg ha-1 of K2O, besides an additional treatment without the addition of fertilizers. The N application increases, on average, by 10 and 35 % the flooded rice yield in years with favorable and unfavorable climatic conditions, respectively. Regardless of the year and genotype, the highest yields are obtained with doses of N between 106 and 200 kg ha-1, with the most profitable dose being the 150 kg ha-1 one (22 % higher than for the absence of N). The hybrids produce an average of 20 % more grains than the IRGA 424 CL cultivar, increasing the profitability by 18 %. In soil with adequate P and K availability, there is no increase in yield due to the application of these nutrients. However, in deficient soil, the fertilization with P and K increases the grain yield by 21 %.

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The hybrid seeds obtained by crossing in wheats should be heavier and a greater number of grains per combination because of more variation and to created powerful plants for next year generations. Therefore, this study was conducted during the winter growing season of 2005-2006 in Transitional Zone Agricultural Research Institute in Eskişehir and to determine the hybrid seeds of single cross and three-way cross compared to each other for 10-grains weight (TGW) and grain number per combination (GC) in separately bread wheat and durum wheat. 224 F1s for single cross and 326 F1s for three-way cross in bread wheat and 56 F1s for single cross and 66 F1s for three-way cross in durum wheat were produced. According to results, GC and TGW in bread wheats were higher values than durum wheats both in single cross and three-way cross. The GC values in three-way cross had higher variation (68.9%) compared the others. The separately mean of GC and TGW of hybrids in single cross both in bread and durum wheat were lower than the means of hybrids in three-way cross (with ratios of 32% and 16.7%, respectively). In brief: three-way cross had more performance for studied traits in wheat hybrids compared to single cross. The reason of such an outcome can be demonstrated in the future by genetic studies.

Well before the green revolution in the 1960s, hybrid maize technology that had originally been developed in the USA spread across the world, starting before the Second World War. This article uses a framework that analyses the type of transfer (materials, knowledge, or capacity), the roles of diverse actors, and farmer demand and its market context, to trace the diffusion of hybrid technology to Latin America, Asia, Europe, and Africa up to 1970. The article also highlights the importance of access to diverse germplasm from the Americas provided by indigenous farmers. A handful of US public institutions promoted the spread of hybrid technology, with US private seed companies sometimes playing a secondary role. However, most cases of successful transfer were led by national scientists embedded in local institutions, who were able to link to local seed systems and farmers. By the mid 1970s, the aggregate impacts of these efforts were of the same magnitude as for the well-known and much publicized green revolution wheat varieties. Nonetheless, adoption of hybrid maize across and within countries was very patchy, relating to differences in scientific capacity, type of farmer, agro-ecology, and complementary investments in seed systems and extension. Consequently, impacts were often highly inequitable. [ABSTRACT FROM AUTHOR]

Depending on the genotype of monoecious plants Cucurbitaceae family may have different gender expressions: predominantly female, mixed and predominantlymale type of flowering. However, the degree of sexual differentiation can be changedunder the influence of abiotic and endogenous factors. Among the chemicals that affect the level of female flowering in pumpkin crops, preparations based on 2-chloroethylphosphonic acid (Ethephon or Etrelle) are the most promising for hybrid seed production. Study of plant response of squash Cucurbita pepo var. giromontina with varying sex expressions on the treatments with Etrelle revealed common conformities and specificities of preparation action in the condition of Krasnodar region. It is shown the use of treatment once is not effective even if the high concentration range, 500-1100 mg/L, was taken. On gender switch was effectively influenced successive plant treatments with Etrelle at stages of 3-5 true leaves in a wide concentration range from 250 to 700 mg /L., where the restraining was that the start of male flower blossoming was 14-25 days after female flower blossoming. K69 line with predominantly female flowering was more responsive to the variation of concentration and frequency of treatments whereas the line K49 with male flowering was less responsive to the frequency of treatments. It is shown that in the range of effective concentrations, Etrelle may have phytotoxic effects on the growth and development of squash plants at the time of restraining flowering of male flowers. It is important to ake that into account when choosing a regime of preparation treatments for chemical castration of maternal forms in hybrid seed production of this crop.

Cultivation of long season hybrid and GMO Bt-hybrid cottons is unique to India. The hybrid technology prevents seed saving, requires annual purchases of high cost seed that leads to sub optimal planting densities. These factors contribute to stagnant low yields and to increases in insecticide use that induce new pests that are increasingly resistant to insecticide and Bt toxins. Subsistence farmers growing rainfed Bt cotton in south and central India have been particularly affected by this hybrid technology. Pure line high-density short-season (HD-SS) rainfed cotton varieties are available or in development that would greatly increase yields, reduce yield variability, decrease costs of seed and insecticides and increase profits. The high costs of Bt hybrid seed make the technology incompatible with the HD-SS applications. The article questions why pure line HD-SS technology has not been implemented in India. [ABSTRACT FROM AUTHOR]

Male sterility enabled commercialization of heterosis in rice but low seed set remains a constraint on hybrid dissemination. We evaluated 216 F6 maintainer lines for agronomic and floral characteristics in augmented design and selected 15 maintainer lines, which were testcrossed with IR58025A. Five backcrosses were conducted to transfer cytoplasmic male sterility (CMS) to select maintainer lines. Newly-bred BC5:6 CMS lines were evaluated for outcrossing rates and agronomic characteristics. There were highly significant differences among 216 F6 maintainer lines for characteristics whose genotypic variance was higher than environmental variance. The phenotypic coefficient of variation was almost the same as the genotypic coefficient of variation, indicating that most phenotypic variation was due to genetics. There were highly significant differences among CMS lines for number of days to 50% flowering and maturity; stigma exertion; panicle exertion, length and weight; spikelet fertility; tillers per plant; plant height; grains per panicle; grain yield per plant; and 1000-grain weight, but not for pollen and panicle sterility during dry and wet seasons. Three CMS lines (CMS3, CMS12, and CMS14), exhibited high outcrossing rates (56.17%, 51.42% and 48.44%, respectively), which had a highly significant, positive correlation with stigma exertion (0.97), spikelet opening angle (0.82), and panicle exertion (0.95). [ABSTRACT FROM AUTHOR]

During the evolutionary history of flowering plants, the appearance of floral nectaries allowed the replacement of pollen by nectar to attract pollinators, allowing lower costs involved in animal pollination by reducing the consumption of pollen. In the hybrid seed productions of entomophilous crops, knowing the levels of nectar secretion of the different lines, the male fertile (MF) and the male sterile (MS) ones, is important to maximize pollen transfers between them. In this study, we start with a review of current methods used to measure nectar secretion, and choose the one that provides a gross secretion rate in order to use it on two winter oilseed rape (Brassica napus L.) lines, the hybrid F1 'Exocet' and its MS parent. We show that oilseed rape has a gross nectar secretion rate that is constant over a period of 6-8 hours during daylight hours, that it has a thermal optimum included between 20 °C and 30 °C, and that the parental MS line secretes about half as much as the hybrid F1 one. These results enable us to propose a rigorous method to compare nectar secretions between lines and varieties. We conclude with the main other variables that should be taken into account to estimate the total amount of nectar produced by a given area of crop. [ABSTRACT FROM AUTHOR]

In soybean, genic male sterility can be utilized as a tool to develop hybrid seed. Several male-sterile, female-fertile mutants have been identified in soybean. The male-sterile, female-fertile ms5 mutant was selected after fast neutron irradiation. Male-sterility due to ms5 was associated with the “stay-green” cotyledon color mutation. The cotyledon color trait in soybean is controlled by two loci, D1 and D2. Association between cotyledon color and male-sterility can be instrumental in early phenotypic selection of sterility for hybrid seed production. The use of such selection methods saves time, money, and space, as fewer seeds need to be planted and screened for sterility. The objectives of this study were to compare anther development between male-fertile and male-sterile plants, to investigate the possible linkages among the Ms5, D1 and D2 loci, and to determine if any of the d1 or d2 mutations can be applied in hybrid seed production. The cytological analysis during anther development displayed optically clear, disintegrating microspores and enlarged, engorged pollen in the male-sterile, female-fertile ms5ms5 plants, a common characteristic of male-sterile mutants. The D1 locus was mapped to molecular linkage group (MLG) D1a and was flanked by Satt408 and BARCSOYSSR_01_1622. The ms5 and D2 loci were mapped to MLG B1 with a genetic distance ~12.8 cM between them. These results suggest that use of the d2 mutant in the selection of male-sterile line may attenuate the cost hybrid seed production in soybean.