Improving Seedling Blast Resistance of Rice CMS Line Taonong1A Through Marker-assisted Selection of the Pigm Gene
To improve seedling blast resistance of rice cytoplasmic male sterile(CMS)line Taonong1A and its maintainer Taonong1B,the Chinese local rice variety Gumei 4 was used as the donor parent harboring the broad-spectrum and durable blast resistance gene Pigm,and the Pigm-tightly-linked codominant marker T9E3 was devel-oped and employed in marker-assisted selection(MAS)breeding practice.T9E3 showed clear and stable polymor-phism between the donor and acceptor parents,amplifying a 926 bp DNA band from Gumei 4 genome,while the PCR product from either genome of Taonong1B or Taonong1A was about 2000 bp.Greenhouse inoculation assay was performed using thirty-two Magnaporthe oryzae isolates collected from different rice areas,Gumei 4 and the im-proved rice lines showed much higher resistance frequency(90.63%)than that of two acceptor parents Taonong1B and Taonong1A(9.38%).Accordingly,Gumei 4 and the improved rice lines showed high-level seedling blast re-sistance(0 grade)but highly susceptible(8 grade)for two acceptor parents in natural nursery.Three blast resistant CMS pure lines(Taonong1A-Pigm-1—Taonong1A-Pigm-3)and the corresponding resistant maintainers(Taonong1B-Pigm-1—Taonong1B-Pigm-3)were preliminarily bred through MAS breeding,and one pair of them,Taonong1A-Pigm-2/Taonong1B-Pigm-2,was screened for potential application duo to the high-level blast resistance and elite sterility,agronomic and yield traits.Taonong1A-Pigm-2 showed complete male sterility with nearly 60%typical a-bortive pollens and 40%round abortive pollens,higher stigma exsertion rate(71.1%)and lower enclosed spikelet rate(33.6%),Taonong1B-Pigm-2 exhibited excellent agronomic and yield trait indexes,such as moderate sowing-heading duration(69 days),plant height(76.2 cm),main panicle length(28.1 cm),panicles per plant(15.8),spikelets per panicle(115.3)and 1000-grain weight(27.7 g).New parent materials were created for the applica-tion of cytoplasmic male sterile(CMS)line hybrid rice breeding,and the comprehensive improvement of seedling blast resistance and characters of Taonong1A and Taonong1B were realized.
国家科技期刊平台
NSTL
万方数据
