水稻籼粳交DH群体中影响白背飞虱抗虫性QTL的检测

分析了水稻籼粳交加倍单倍体(DH)群体中影响白背飞虱抗虫性和感虫性的QTL.虽然DH株系的亲本窄叶青8号和京系17没有拒取食抗性,但是白背飞虱在6个DH株系中的取食受到了强烈的抑制,可能属超亲分离.在第3染色体的粳型片段中检测到1个影响蜜露分泌的微效QTL.粳稻亲本京系17具有杀卵抗性.DH株系中的杀卵特性是通过叶鞘上杀卵反应产生的坏死症状表现的.在DH株系分蘖早期和中期,将4个杀卵作用的QTL定位在第1、2、6和8染色体的粳型片段上.出现在分蘖中期的另一个QTL被定位在第9染色体的籼型片段上.在分蘖盛期至孕穗期,杀卵位点减少至2个.整个试验期间对每个DH株系的最高杀卵级别的分析显示,在染色体2、6和9上共有4个QTL.两个主效QTL位于近邻第6染色体的粳型片段.在第1、3和5染色体上检测到3个影响第2代白背飞虱若虫密度的QTL.第3染色体上起主要作用的QTL源自粳稻亲本;第5染色体上的微效QTL源自籼稻亲本.两个白背飞虱为害的QTL位于第8和第10染色体的籼型片段,另一个QTL位于第3染色体的粳型片段.这些QTL被认为与水稻品种对白背飞虱田间抗性表达有关.

Detection of QTLs Affecting Whitebacked Planthopper Resistance in an Indica/Japonica Doubled Haploid Rice Population

Quantitative trait loci (QTLs) affecting the whitebacked planthopper (WBPH) resistance and susceptibility in an indica/japonica doubled halpoid (DH) rice population were analyzed. Although the parents of DH lines, Zhaiyeqing 8 (ZYQ-8, indica) and Jingxi 17 (JX-17, japonica), had no sucking inhibitory resistance, WBPH sucking was strongly suppressed in six DH lines for possible transgressive segregation. A minor QTL affecting honeydew excretion was detected at a japonica segment of chromosome 3. Japonica parent JX-17 had ovicidal resistance to WBPH. Ovicidal trait in DH lines was phenotyped by necrotic symptoms on the leaf sheaths due to ovicidal response. Four ovicidal QTLs were located on japonica segments of chromosomes 1, 2, 6, and 8 in DH lines at early- and mid- tillering stages. One more QTL appearing at mid- tillering stage was located on an indica segment of chromosome 9. The ovicidal loci reduced to two at the maximum tillering to booting stage. Analysis based on the maximum score of ovicidal symptom for each DH line throughout the experimental period revealed four QTLs on chromosomes 2, 6 and 9. Two major QTLs were located closely on japonica segments of chromosome 6. Three QTLs affecting the density of the second-generation WBPH nymphs were detected on chromosomes 1, 3 and 5. A main-effect QTL on chromosome 3 was derived from the japonica parent. A minor QTL on chromosome 5 came from the indica parent. Two QTLs for WBPH damages were located on indica segments of chromosomes 8 and 10, and the other QTL on a japonica segment of chromosome 3. These QTLs were considered to be associated with the expression of field resistance of rice varieties to WBPH.