Abstract
The result of the study contributes to enhancing and sustaining future livelihoods and food security in Vietnam vis-a-vis climate change. An innovative strategy based on marker-assisted backcrossing (MABC) was used to transform popular rice variety AS996 into the one can tolerate submergence while maintaining its original characteristics preferred by farmers and consumers. The submergence tolerance QTL SUB1 counts for up to 70% of the submergence tolerant and provides a marked improvement of submergence tolerance in all genetic backgrounds and environments tested so far. Parental diversity was carried out with 460 markers. Of which, 53 polymorphic markers were used for assessment on BC1F1, BC2F1 and BC3F1 generations. The best BC1F1 plant was P422 with highest recipient allele was 87.5%, while the additional chosen plants were P412, P428, P215 and P39 (81% - 84%). All these plants were used to develop BC2F1 generation. The six BC2F1 plants were used to develop BC3F1 and BC2F2 were the plants number P422-11 and P422-14 having 93.75% recipient alleles and P422-12, P422-3, P39-17, P39-25 having 92.25% recipient alleles. Total of 445 BC3F1 plants were confirmed the introgresion of SUB1 using ART5 and SC3. After three generations of backcrossing, application of MABC resulted in the best BC3F1 individual P422-14-177 with 100% of recipient alleles based on the number of 53 markers used with only the introgression size of SUB1 was 0.3Mb between ART5 and SC3. Phenotyping was carried out on BC3F1 and BC2F2 of the selected lines. The survival ratio of these selected lines and IR64SUB1 were the same. It convinced the successfully introgress SUB1 into AS996 rice variety. The breeding line BC4F1 having 100% genetic background of donor variety is ready for develop new submergence tolerant rice variety ASS996-SUB1 to cope with climate change.
Highlights
Vietnam is among the five countries hardest hit by climate change
Total of 445 BC3F1 plants were confirmed the introgresion of SUB1 using ART5 and SC3
After three generations of backcrossing, application of marker-assisted backcrossing (MABC) resulted in the best BC3F1 individual P422-14-177 with 100% of recipient alleles based on the number of 53 markers used with only the introgression size of SUB1 was 0.3 Mb between ART5 and SC3
Summary
Vietnam is among the five countries hardest hit by climate change. The frequency of natural disasters like typhoon, flooding etc... are increasing annually. Submergence caused by flash-flooding is one of the most serious impacts to the agricultural productions of the country. In. Vietnam, rice is the number one agricultural product, for second largest exporter and accounts for. Of the 4.5 million ha rice area, more than one million ha is affected by flooding, remains for at least one to two weeks in many parts of the country. Depending on the timing of flood with respect to growth stage, shorter duration and shallow flashfloods can result in less than 10% production losses. The maximum number of recombinant and background markers used was 8 for chromosome 9. The microsatellite markers that revealed fixed (homozygous) alleles at non-target loci in one generation were not screened in the backcross generation. The segregants with fixed donor alleles were discarded from the selection. The best plant was P422, while the additional chosen plants were
Sign-in/Register to view highlights & summary 
Published Version (
Free)
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 call