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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.

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 %.

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.

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.

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.

Resumen: Se evaluó la viabilidad del polen de berenjena (Solanum melongena L.) mediante el método de germinación in vitro. Botones florales de la variedad Lila criolla con características de pre-antesis fueron colectados de las 07:00 a las 08:00 horas. Los granos de polen fueron extraídos con un vibrador eléctrico y rehidratados en cámara húmeda durante dos horas a temperatura de 25 ºC. Posteriormente, para la germinación en condiciones in vitro, los granos fueron dispersados, utilizando un pincel, en un medio de cultivo constituido por 100 g de sacarosa (C12H22O11), 500 mg de nitrato de calcio [Ca (NO3)2 4H2O], 120 mg de sulfato de magnesio (MgSO4), 100 mg de nitrato de potasio (KNO3) y 120 mg de ácido bórico (H3BO3) disueltos en 1.000 mL de agua destilada. Seguidamente, se agregaron 10 g de agar y el pH fue ajustado a 6,0. El polen fresco fue incubado durante ocho horas con lecturas cada dos horas. Los resultados indican que el método es confiable para cuantificar la viabilidad de granos de polen, ya que después de ocho horas de incubación se logró un 79% de germinación, 0,50 mm de longitud del tubo polínico y 0,0532 mm de diámetro del mismo. Por lo tanto, el uso de polen con ocho horas de almacenamiento es favorable para la producción de semilla híbrida a través de la hibridación artificial, por haber registrado un aumento de germinación de 0,4942% con efecto cuadrático, por cada hora de incubación.Abstract: We assessed the viability of pollen of eggplant (Solanum melongena L.) using in vitro germination method. The collection of flower buds in pre-anthesis of the Lila criolla variety was carried out in the morning from 07:00 to 08:00 hours. Pollen grains were extracted with an electric vibrator and rehydrated in a humid chamber for two hours at a temperature of 25 ºC. Subsequently, for germination in vitro, were dispersed, using a paintbrush, in a culture medium container 100 g of saccharose (C12H22O11), 500 mg of calcium nitrate [Ca (NO3)2 4H2O], 120 mg of magnesium sulfate (MgSO4), 100 mg of potassium nitrate (KNO3) and 120 mg boric acid (H3BO3) dissolved in 1,000 mL of distilled water. Subsequently, it was added 10 g of agar and the pH was adjusted to 6.0. The fresh pollen was incubated in a culture medium for eight hours and observations were made every two hours. The results indicate that the method used is reliable to quantify the viability of pollen grains, because after eight hours of incubation achieved the highest percentage of germination (79%), the pollen tube length was of 0.50 mm and diameter of 0.0532 mm. Therefore, the use of pollen with 8 hours of storage is favorable for hybrid seed production through artificial hybridization, to have been an increase of 0.4942% germination with quadratic effect, for each hour of incubation.

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).

This paper reviews sunflower hybrid seed processing at Institute of Field and Vegetable Crops Novi Sad with all practical, technical and technological solutions. Additionally, efforts of Institute's employees are presented here in creating new technical solutions, particularly machines, aimed at their adaptations in existing sunflower seed processing, in order to get better quality and quantity of the processed seed. The paper also reviews original solution of the seed processing improvement with the new machines, regarding their position in the system and their connection in the semiautomatic operation system, with the possibility of independent operation. Seed processing results in high quality sunflower hybrid seed produced and ready for the severe market competition. .

The estimated market value for vegetable seeds in Brazil, based on prices paid by producers, reached around R$ 300million in 2007. Seeds from open-pollinated cultivars accounted for only 18 %. This data clearly indicates the changeover fromopen-pollinated to hybrid seeds in recent decades in the main varietal segments of the Brazilian vegetable market. This lecture willoutline a historical retrospective of the pioneer activities of genetic improvement of vegetable crops targeting open-pollinatedcultivars in breeding programs conducted by the public universities and research institutes and their impact on the development ofthe Brazilian horticulture. The current situation, challenges and future prospects will also be discussed.