Double Haploid Development and Assessment of Androgenic Competence of Balkan Pepper Core Collection in Bulgaria

This study was designed to assess the androgenic potential of 180 pepper accessions and 11 progenies (four F1 and seven BC) possessing PMMoV resistance in order to complement an ongoing pepper breeding program. The experiment was carried out in 10 replications with 20 anthers for each accession in two different induction mediums from 2017 to 2019. The highest androgenic response was observed in culture medium 17-2 but differences between two mediums were nonsignificant. From a total of 191 genotypes, 102 genotypes expressed a potential for direct embryogenesis. Embryo induction was seen to be genotype-dependent and decreased in the following order: Pumpkin > Conical > Bell or blocky > Round > Elongate as the most responsive genotypes with over 10% reacted anthers being observed in CAPS-23, CAPS-29, CAPS-127, CAPS-157, CAPS-169, F1 and BC 887 derived from CAPS-23. The number of regenerated plants was higher in the conical group and least in the round varietal group. Regenerated plants were examined visually and by flow cytometry for identification of spontaneous doubled haploids (DH) and haploids. Those originating from F1 and BC progenies were additionally evaluated by a CAPS marker targeting L4 allele for resistance against PMMoV. Obtained results revealed two groups consisting of homozygous susceptible and resistant plants. Therefore, use of anther culture in ongoing breeding will greatly facilitate the pepper genetic improvement.

Vegetable Breeding Strategies

Variation present in vegetables provides plentiful of opportunity for development of breeding lines and hybrids. Germplasm development depends on incorporation of approaches such as MAGIC population, use of wild relatives, genetic transformation for transferring resistance gene and gene pyramiding. These approaches are most reliable to improve qualitative as well as quantitative characters. Since conventional methods are time consuming, molecular techniques are also utilized at appropriate stages to enhance swiftness of line development. Molecular approaches includes many tools but marker assisted selection is best to use in vegetable breeding programme. It helps to rapid back cross breeding also selection of resistance or qualitative lines from segregating populations. Double haploid is one of finest methods to create diverse pure lines in short interval. There are many ways to incorporate diverse gene in single line through double haploid technology. Hybridization mating such as line x tester or diallel are common methods instead combination breeding method is very result oriented as compared with others. The success rate of specific combination breeding is as much as double as associated with other ones.

Pengaruh Konsentrasi Dan Lama Inkubasi Kolkisin Terhadap Duplikasi Kromosom Planlet Terung (Solanum melongena L.) Haploid Galur Aksesi Hasil Kultur Antera

The purpose of this study was to determine the effect of colchicine on chromosome duplication and to determine the best colchicine concentration and incubation time for haploid eggplant chromosome duplication results from anther culture. Laboratory experiments have been carried out at PT. East West Seed Indonesia, Benteng Village, Campaka District, Purwakarta from March to June 2020. With an altitude of 69 m above sea level. The environmental design used in this study was a completely randomized design consisting of 7 treatments and repeated 4 times. Colchicine treatment design A = Control, B = colchicine 0.05% 24 hours incubation, C = colchicine 0.05% 48 hours incubation, D = colchicine 0.1% 24 hours incubation, E = colchicine 0.1% 48 hours incubation, F = kolkisisn 0.15% incubation 24 hours, G = colchicine 0.15% incubation 48 hours. The responses observed were contamination, callous plantlets, rooted plantlets, live plantlets, haploid plantlets, double haploid plantlets, triploid plantets and unreadable ploidy check results. The results showed that the colchysis concentration and incubation time had an effect on the duplication of haploid eggplant plantlet chromosomes resulting from anther culture. And giving colchicine at a concentration of 0.05% with an incubation time of 48 hours and a colchicine concentration of 0.1% with an incubation time of 48 hours had a significant effect on the double haploid plantet of 23.44%.

Development of supermale and all-male Atlantic salmon to research the vgll3 allele - puberty link

Background Farmed Atlantic salmon are one of the most economically significant global aquaculture products. Early sexual maturation of farmed males represents a significant challenge to this industry and has been linked with the vgll3 genotype. However, tools to aid research of this topic, such as all-male and clonal fish, are still lacking. The present 6-year study examined if all-male production is possible in Atlantic salmon, a species with heteromorphic sex chromosomes (males being XY, females XX), and if all-male fish can be applied to further explore the vgll3 contribution on the likelihood of early maturation. Results Estrogen treatment of mixed sex yolk sac larvae gave rise to one sexually mature hermaphrodite with a male genotype (XY) that was used to produce both self-fertilized offspring and androgenetic double haploid (dh) offspring following egg activation with UV treated sperm and pressure shock to block the first mitotic division. There were YY supermales among both offspring types, which were crossed with dh females. Between 1 and 8% of the putative all-male offspring from the eight crosses with self-fertilized supermales were found to have ovaries, and 95% of these phenotypic females were also genetically female. None of the offspring from the one dh supermale cross had ovaries. When assessing the general contribution of the vgll3 locus on the likelihood of early post-smolt sexual maturation (jacking) in the all-male populations we found individuals that were homozygous for the early maturing genotype (97%) were more likely to enter puberty than individuals that were homozygous for the late maturing genotype (26%). However, the likelihood of jacking within individuals with an early/late heterozygous genotype was higher when the early allele came from the dam (94%) compared to the sire (45%). Conclusions The present results show that supermale Atlantic salmon are viable and fertile and can be used as a research tool to study important aspects of sexual maturation, such as to further explore the sex dependent parental genetic contribution to age at puberty in Atlantic salmon. In addition, we report the production of viable double haploid supermale fish.

Effect of Chemical Composition of Nutritive Medium and Explant Size Over Androgenetic Response in Microspore Culture of Brassica oleracea L.

The dimension of the bud is a key factor for the orientation of microspore culture and the success of obtaining double haploid plants as it is a strong correlation between bud size and the developmental stages of microspores, and it is specific for each plant species and genotype. Our study was focused to determine the correlation between morphological characteristics, namely floral bud size and specific microspore developmental stages in order to determine the proper size, suitable for a successful protocol of obtaining double haploid plants in Brassica oleracea var. italica. Thus, we tested four bud sizes ranging from 2.0 to 4.0 mm measured from the base to the tip of the bud. After the statistical analysis of the results it can be emphasized that the best results were obtained in the case of using as a source of microspores the flower buds with the size between 3.1-3.5 mm. At this dimension, the share of microspores in the uninucleate stage, predominantly in the late uninucleate stage, is 90%, thus ensuring a homogeneous population of microspores in the optimum stage of development. Their evolution is predominantly embryogenic, the percentage of microspores following the gametophytic pathway is reduced, by only 9.12%.