Breeding and utilization of good-quality indica rice CMS line Qing A with blast resistance

ObjectiveThe present study bred new CMS lines with blast resistance and good quality,and accordingly bred hybrid varieties with blast resistance and good quality,in order to provide upgraded varieties and ensure grain security.MethodTaking blast-resistant rice Gui 2 as parent,crossed and multiple-crossed Gui 2 with offspring of Shan B×Bo B.Then selected lines back-crossed with Bo A and bred into indica rice CMS line Qing A.Qing A test-crossed with restorer lines and obtained quality hybrid variety with blast resistance.ResultQing A enjoyed following features:blast resistance level 1-3,head rice rate 58.5%,kernel length 5.4 mm,length-width ratio 3.0,chalky rice rate 4%,chalkiness degree 0.5%,transparency grade 2,alkali spread value (ASV) 6.3,gel consistency 68 mm,amylose content 25.1%,pollen sterility 100.000%.Hybrid combinations obtained through test-crossing with Qing A had following advantages:response to temperature,high yield,good grain quality and strong resistance.ConclusionQing A is a CMS line with strong blast resistance,good grain quality,complete pollen sterility,stable sterility,favorable flowering habits,excellent agronomic trait and high combining ability.Its hybrid combinations show wide adaptability,high yield,good grain quality and strong blast resistance.