Double haploids

Anther culture is a biotechnological technique that can be used for production of pure lines in many species. In order to access the anther culture response in Brassica juncea, four different genotypes (RH 406, RH 555, RH 749 and RH 832) and their F 1 's with Ogura Restorer (OR) as the background were evaluated using two basal media viz., MS and B5 with different concentrations of phytohormones. Anthers were cultured at uninucleate stage and subsequent plant regeneration was studied on MS media with different concentrations and combinations of phytohormone. Maximum callusing (%) response of anthers was observed in F 1, OR x RH 749 (20.37+1.44) and maximum percent embryogenic calli obtained were 20.35+2.68 in same genotype on medium supplemented with B5 as basal medium with 100 mg/l sucrose, 30 mg/l glutathione, 100 mg/l serine, 0.05 mg/l BAP, 0.5 mg/l NAA and 10 mg/l silver nitrate. Rooting and hardening of plantlet was done on MS medium supplemented with different concentration of NAA and IBA. Out of sixteen anther culture media combinations tried, the best media were found to be ACM15 and ACM16 (containing B5 as basal medium with 100 mg/l sucrose, 30 mg/l glutathione, 100 mg/l serine, 0.05 mg/l BAP, 0.5 mg/l NAA and 10 mg/l silver nitrate in ACM15 and 20 mg/l silver nitrate in ACM 16) for all parents and F 1 's.

A study was undertaken to develop an effective protocol to
generate doubled haploid plants from a proprietary Mahyco
hybrid MRP5401. A total of 20,300 anthers were plated on
four different DH media (basal N6 + phytohormones) and
obtained a callus induction success rate of 1.52%, of which
0.48% developed into green plants. A total of 232 lines were
obtained of which, 98 lines showed homozygosity in DH2-
3 generations. Well established DH lines from MRP5401 in
DH3 generation had early flowering and yield gain.

The objective of this study was to develop a simple anther culture protocol for a range of Saudi wheat genotypes. Seven wheat genotypes were evaluated in anther culture on five different medium protocols for their ability to initiate callus and green plants. The estimates of significance for the effects of genotypes, and medium protocols used, and their interactions on callus induction, callus weight and shoot formation derived from anther explants indicated that the in vitro traits were significantly influenced by the genotypes, medium protocols, and their interactions. The percentage of explants that developed calli ranged from 0.41% (Lang) to 15.39% (Irena) averaged across the five medium protocols with an average 4.45%. The genotype Irena produced the highest average means of shoot formation (69.65%) across medium protocols. The genotype Yecora Rojo (13.73%) was significantly inferior to all other tested genotypes for shoot formation.

Anther culture is a biotechnology technique that can be used for production of pure lines in many species. The aim of this experiment is to study comparative response of anther culture on different genotypes of Brassica. In order to access the effect of anther culture response in different genotypes of Brassica, three varieties of B. napus [GSL1, DGS1 and RSPN25) and three varieties of Brassica juncea (RSPR01, Varuna and Kranti) were evaluated. The best response of callus induction was observed in MS medium supplemented with 2, 4-D (1.0 mg l -1 ) and NAA (0.5 mg l -1 ). Enhancement of regeneration of plantlets was achieved by sub culturing embryogenenic callus on media containing different concentrations of cytokinins [BAP and Kinetin] and the best response of embryogeniccalli was got with kinetin [2.0 mg l 1 ]. The best rooting was achieved with 0.4 mg/l IBA. After 5 days of rooting root samples were taken for confirmation of haploid nature of the plants. Haploid frequency was more...

The Balkan pepper breeding program aims to use in vitro embryogenesis (anther culture) to develop doubled haploid pepper lines with valuable traits. We analyzed the effectiveness of microspore embryogenesis on 17 pepper genotypes comprised of varieties, breeding lines, and F 1 hybrids of different varietal types (conical, bell shape, and kapia) and characterized the agronomic traits of newly generated doubled haploid lines. The highest androgenic potential was observed in the variety Stryama and breeding line 560/06 with 9.55 and 13.00% reacted anthers, respectively. Of the 186 regenerated plants, 147 were successfully adapted with a survival index of 79.03%. Flow cytometry analysis showed that the haploid:diploid ratio of regenerants was 1.5:1. All diploid plants were confirmed to be androgenic in origin. There were significant differences in terms of quantitative fruit characteristics of length, width, weight, pericarp weight, pericarp thickness, and productivity per plant among the diploid lines. Also, androgenic lines 21, 23, and 74 derived from Stryama and line 55 obtained from Zlaten medal 7 were distinguished with higher values of some fruit traits compared to initial genotypes. Additionally, several androgenesis lines (Stryama lines 21, 23, and 74, and Zlaten medal 7 line 55) scored higher for some fruit traits compared to the initial genotype. These results show that anther culture is a promising tool for the creation of Balkan pepper breeding lines with improved traits. Keywords Androgenesis Á Doubled haploid breeding Á Haploid:diploid regenerants Á Balkan pepper Á Kapia Abbreviations DH Doubled haploid PPFD Photosynthetic proton flux density CV Coefficient of variation

Anther or microspore culture induced haploid and double haploids (DH) are increasingly being utilized by breeders since it can shorten breeding time by achieving complete homozygosity within a single generation. Pepper (Capsicum annuum L.) is one of the most important vegetables, distinguished by its high level of heterozygosity, making the breeding process very laborious and long. Fourteen different DH lines were obtained as a result of anther culture of four parental genotypes. Data from different plant and fruit morphological traits as well as quality traits including vitamin C, dry matter content, total polyphenols and antioxidant activity were collected. A total of 47 different descriptors for fruit morphology and color were characterized using Tomato Analyzer v. 3 software. Findings from this research revealed significant variation of fruit morphology, quality and productivity traits between DH lines and their respective parental genotypes. Among these studied 14 DH lines, 42.9% were superior to the parental genotypes for fruit weight, width, fruit wall thickness, and usable part of the fruits. As compared to parental genotypes, DH lines exhibited higher values for tested fruit quality traits and dry matter content. Multivariate analysis allowed us to identify the trait combination that contributed to the total variation. A total of eight principle components (PCs) explained 95.4% variation with PC1 and PC2 contributing 32.4% and 21.1%, respectively. Pepper androgenesis clearly indicates its usefulness as a well established technique that can allow pepper breeders to save the time and breeding resources by expediting the breeding process. Our research findings prove the advantages of pepper androgenesis to utilize the diversity of pepper genetic resources and development of novel pepper breeding lines to utilize in future breeding.

A study was undertaken to develop an effective protocol to generate doubled haploid plants from a proprietary Mahyco hybrid MRP5401. A total of 20,300 anthers were plated on four different DH media (basal N6 + phytohormones) and obtained a callus induction success rate of 1.52%, of which 0.48% developed into green plants. A total of 232 lines were obtained of which, 98 lines showed homozygosity in DH2–3 generations. Well established DH lines from MRP5401 in DH3 generation had early flowering and yield gain.

Anther or microspore culture induced haploid and double haploids (DH) are increasingly being utilized by breeders since it can shorten breeding time by achieving complete homozygosity within a single generation. Pepper (Capsicum annuum L.) is one of the most important vegetables, distinguished by its high level of heterozygosity, making the breeding process very laborious and long. Fourteen different DH lines were obtained as a result of anther culture of four parental genotypes. Data from different plant and fruit morphological traits as well as quality traits including vitamin C, dry matter content, total polyphenols and antioxidant activity were collected. A total of 47 different descriptors for fruit morphology and color were characterized using Tomato Analyzer v. 3 software. Findings from this research revealed significant variation of fruit morphology, quality and productivity traits between DH lines and their respective parental genotypes. Among these studied 14 DH lines, 42.9% were superior to the parental genotypes for fruit weight, width, fruit wall thickness, and usable part of the fruits. As compared to parental genotypes, DH lines exhibited higher values for tested fruit quality traits and dry matter content. Multivariate analysis allowed us to identify the trait combination that contributed to the total variation. A total of eight principle components (PCs) explained 95.4% variation with PC1 and PC2 contributing 32.4% and 21.1%, respectively. Pepper androgenesis clearly indicates its usefulness as a well established technique that can allow pepper breeders to save the time and breeding resources by expediting the breeding process. Our research findings prove the advantages of pepper androgenesis to utilize the diversity of pepper genetic resources and development of novel pepper breeding lines to utilize in future breeding.

Ten doubled haploid (DH) lines of winter barley with an increased range of freezing/drought tolerance were used to identify phytohormones involved in plant stress acclimation. Cold hardening and drought stress were applied at the most critical stages of plant development on young seedlings and heading plants, respectively. The level of the phytohormones was significantly higher at heading, more than 5-fold in respect of salicylic acid (SA) and total brassinosteroids (BRs) and 1.7-fold in the case of abscisic acid (ABA). Moreover, the spectrum of detectable BRs increased from one—homocastasterone (HCS)—found in seedlings to four BRs identified in heading plants [HCS, castasterone (CS), teasterone and dolicholide], with the last one detected for the first time in cereal species. To some extent freezing tolerance seems to be determined by native hormonal status as control seedlings of tolerant DH lines contained 1.4- and 2.3-fold lower amount of ABA and HCS and 2.3-fold higher amount o...

Anther or microspore culture induced haploid and double haploids (DH) are increasingly being utilized by breeders since it can shorten breeding time by achieving complete homozygosity within a single generation. Pepper (Capsicum annuum L.) is one of the most important vegetables, distinguished by its high level of heterozygosity, making the breeding process very laborious and long. Fourteen different DH lines were obtained as a result of anther culture of four parental genotypes. Data from different plant and fruit morphological traits as well as quality traits including vitamin C, dry matter content, total polyphenols and antioxidant activity were collected. A total of 47 different descriptors for fruit morphology and color were characterized using Tomato Analyzer v. 3 software. Findings from this research revealed significant variation of fruit morphology, quality and productivity traits between DH lines and their respective parental genotypes. Among these studied 14 DH lines, 42.9% were superior to the parental genotypes for fruit weight, width, fruit wall thickness, and usable part of the fruits. As compared to parental genotypes, DH lines exhibited higher values for tested fruit quality traits and dry matter content. Multivariate analysis allowed us to identify the trait combination that contributed to the total variation. A total of eight principle components (PCs) explained 95.4% variation with PC1 and PC2 contributing 32.4% and 21.1%, respectively. Pepper androgenesis clearly indicates its usefulness as a well established technique that can allow pepper breeders to save the time and breeding resources by expediting the breeding process. Our research findings prove the advantages of pepper androgenesis to utilize the diversity of pepper genetic resources and development of novel pepper breeding lines to utilize in future breeding.

Ten doubled haploid (DH) lines of winter barley with an increased range of freezing/drought tolerance were used to identify phytohormones involved in plant stress acclimation. Cold hardening and drought stress were applied at the most critical stages of plant development on young seedlings and heading plants, respectively. The level of the phytohormones was significantly higher at heading, more than 5-fold in respect of salicylic acid (SA) and total brassinosteroids (BRs) and 1.7-fold in the case of abscisic acid (ABA). Moreover, the spectrum of detectable BRs increased from one-homocastasterone (HCS)-found in seedlings to four BRs identified in heading plants [HCS, castasterone (CS), teasterone and dolicholide], with the last one detected for the first time in cereal species. To some extent freezing tolerance seems to be determined by native hormonal status as control seedlings of tolerant DH lines contained 1.4-and 2.3-fold lower amount of ABA and HCS and 2.3-fold higher amount of SA in comparison to freezing-sensitive ones. Such dependency was not observed in heading plants as significant variation in CS content was the only detected difference. Under stress treatments, tolerant DH lines accumulated significantly lower (75-81%) amount of ABA, which probably reflected lower stress intensity resulting from another defence strategy. In contrast, stress-induced significant almost 2-fold increase in HCS/CS and 2-3-fold decrease in SA content specific for tolerant DH lines of barley suggest the involvement of these molecules in freezing/drought defence. Detected correlations suggest their interaction with nonspecific peroxidase and low molecular weight antioxidants.