以分子标记辅助选择育成抗条纹叶枯病水稻新品种“武陵粳1号”

条纹叶枯病是21世纪以来江苏省最重要的水稻病害之一。食味品质较优的主栽品种武育粳3号因高度感染该病而种植面积锐减。本研究以镇稻88为抗条纹叶枯病毒病基因Stvb-i的供体亲本，采用回交育种策略，改良武育粳3号的抗条纹叶枯病性能。在连续回交和自交过程中，以紧密连锁的双侧分子标记对Stvb-i进行“前景”选择，同时对后代与轮回亲本遗传背景的相似程度进行分子标记辅助“背景”选择，在短期内育成抗条纹叶枯病的“武育粳3号”，命名为“武陵粳1号”。新品种保持了原品种的基本农艺性状、丰产性、稳产性和优异的食味品质，并大幅度提高了其条纹叶枯病抗性水平，在江苏省多点抗性鉴定试验中的平均病株率仅为4.4%，极显著低于原品种(53.2%)。

A New Rice Cultivar "Wulingjing 1" with Resistance to Rice Stripe Virus Bred by Marker Assisted Selection

Rice stripe virus disease is one of the most serious diseases in rice production area of Jiangsu province since 2002. A commercial rice cultivar with excellent food taste-quality, Wuyujing 3, was highly susceptible to the disease and was improved through the MAS strategy in a backcross project with “Zhendao 88” as donor parent of resistance gene Stvb-i. In each backcross generation, we selected the progenies with Stvb-i based on the closely flanked markers. In advanced backcross generations, the marker’s detection for genetic background of selected plants was performed, along with the estimate by the eye for the similarity of selected plants to recurrent parent in synthetic agronomic traits. As a result, a new cultivar, Wulingjing 1, was fleetingly bred in BC₃F₄ generation, whose resistance to the disease was significantly increased and main characters especially on excellent taste-quality were consistent with those of the recurrent parent Wuyujing 3. In resistance identification tests with multiple locations organized by Seed Management Station of Jiangsu Province, the average percent of affected plants of the new cultivar was only 4.4% and significantly lower than that of recurrent parent (53.2%).