Abstract
DH (Doubled haploid) is the immortal mapping population and an outcome of single meiotic cycle, contributed from male partner. An improved procedure was developed for high frequency androgenesis in japonica genotypes, K-332 and GS-88 and their F1s. A total of 207 fertile, green, di-haploid plants were generated from K-332 × GS-88 hybrids using the improved anther culture protocol. The investigation was carried out to evaluate callus induction potential and regeneration response for the genotypes and the derived F1s on N6 media and modified N6 media (N6M). Whereas, N6 failed to induce callusing, agarose solidified N6M media supplemented with 4% maltose, growth regulators; NAA (2 mg/l), 2, 4-D (0.5 mg/l), Kinetin (0.5 mg/l), and silver nitrate induced high calli percentage of 27.6% in F1s, 9.5% and 6.7% in GS-88 and K-332 respectively. Murashige and Skoog (MS) media supplemented with 3% sucrose, and the hormonal combination BAP (2 mg/l), Kinetin (1 mg/l) and NAA (1 mg/l) induced high green shoot regeneration rates (0–60.0%). The effect of cold pre-treatment at 4°C and the stage of anther collection and their interaction was studied. The effect of cold pre-treatment (CP) of collected boots at 4°C (for CP2: 2, CP4: 4, CP6: 6 and CP8: 8 days) at different stages of panicle emergence (BES4-6: 4–6, BES7-10: 7–10, BES11-13: 11–13, BES>13: more than 13 inches was worked out in relation to the effect on response of calli induction, albino regeneration, green plant regeneration and number of shoots/green calli. CP referred to the number of days for which the collected boots were incubated before they were inoculated. BES was the length (inches) between flag leaf and penultimate leaf at the time of boot collection. We concluded that CP6 and BES7-10 showed better response to callus proliferation and regeneration of plantlets across genotypes. The appropriate pre-treatment, stage of anther collection and favourable media composition resulted in high calli induction and green plant regeneration rates in recalcitrant japonica genotypes. The modified N6 media resulted into efficient callus induction and is expected to be useful for studies which aim at rapid generation of mapping populations for genetic studies.
Highlights
Doubled haploids (DHs) are plants derived from a single isolated microspore which undergoes diploidization either naturally or artificially to form homozygous diploids
A set of 35 SSR markers were assayed for establishment of parental polymorphism between the parents K-332 and GS-88, of which four (11.4%) markers were found to be polymorphic (S3 Fig)
Following the previous research which demonstrated the positive effect of CuSO4 on anther culture in barley, CuSO4 (0.025 mg/l) was included in the N6 media (N6M) media [14] (Table 1), besides the use of hormones, NAA, 2-4-D and Kinetin
Summary
Doubled haploids (DHs) are plants derived from a single isolated microspore which undergoes diploidization either naturally or artificially to form homozygous diploids. Development of a reliable and efficient regeneration system, including callus induction and differentiation or plant regeneration is pre-requisite for successful development of doubled haploid mapping population in rice. Anther culture technique entails a two-step process: a: calli induction from microspores present within the anther sacs, b: regeneration of green plants from the induced calli. Successful androgenesis depends upon a number of factors such as genotype of pollen donor, stage of pollen development, panicle pre-treatment, culture medium, plant growth regulators, type of sugar and addition of adjuvant, etc. We have reported the optimization of culture media and regeneration protocol for high frequency androgenesis and green plant regeneration from anthers of two genotypes, K-332 and GS-88 and the resulting F1s. The study highlights the ideal stage of pollen harvesting and pre-treatment process that may be vital for improvement of efficiency of anodrogenesis response in rice
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
