Xue Weiya, Haynes Kathleen G, Clarke Christopher R, Qu Xinshun
Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, PA, United States.
Genetic Improvement of Fruits and Vegetables Laboratory, US Department of Agriculture Agricultural Research Service, Beltsville, MD, United States.
Front Plant Sci. 2022 Mar 25;13:851538. doi: 10.3389/fpls.2022.851538. eCollection 2022.
Early blight, caused by the fungus , is one of the most economically important diseases of potatoes worldwide. We previously identified a tetraploid potato clone, B0692-4, which is resistant to early blight. To dissect the genetic basis of early blight resistance in this clone, a full-sib tetraploid potato population including 241 progenies was derived from a cross between B0692-4 and a susceptible cultivar, Harley Blackwell, in this study. The population was evaluated for foliage resistance against early blight in field trials in Pennsylvania in 2018 and 2019 and relative area under the disease progress curve (rAUDPC) was determined. The distribution of rAUDPC ranged from 0.016 to 0.679 in 2018, and from 0.017 to 0.554 in 2019. Broad sense heritability for resistance, as measured as rAUDPC, was estimated as 0.66-0.80. The population was also evaluated for foliar maturity in field trials in Maine in 2018 and 2020. A moderate negative correlation between rAUDPC and foliar maturity was detected in both years. A genetic linkage map covering a length of 1469.34 cM with 9124 SNP markers was used for mapping quantitative trait loci (QTL) for rAUDPC and foliar maturity. In 2018, three QTLs for early blight were detected; two of them on chromosome 5 overlapped with QTLs for maturity, and one of them on chromosome 7 was independent of maturity QTL. In 2019, six QTLs for early blight were detected; two QTLs on chromosome 5 overlapped with QTLs for maturity, and the other four QTLs did not overlap with QTLs for maturity. The identification of these QTLs provides new insight into the genetic basis of early blight resistance and may serve as sources for marker-assisted selection for early blight resistance breeding.
由该真菌引起的早疫病是全球马铃薯最重要的经济病害之一。我们之前鉴定出一个四倍体马铃薯克隆系B0692 - 4，它对早疫病具有抗性。在本研究中，为剖析该克隆系中早疫病抗性的遗传基础，通过B0692 - 4与一个感病品种哈雷·布莱克韦尔杂交，获得了一个包含241个后代的全同胞四倍体马铃薯群体。在2018年和2019年于宾夕法尼亚州进行的田间试验中，对该群体的叶片早疫病抗性进行了评估，并测定了病情进展曲线下的相对面积（rAUDPC）。2018年rAUDPC的分布范围为0.016至0.679，2019年为0.017至0.554。以rAUDPC衡量的抗性广义遗传力估计为0.66 - 0.80。在2018年和2020年于缅因州进行的田间试验中，还对该群体的叶片成熟度进行了评估。在这两年中均检测到rAUDPC与叶片成熟度之间存在中等程度的负相关。使用一个覆盖长度为1469.34厘摩、含有9124个单核苷酸多态性（SNP）标记的遗传连锁图谱，对rAUDPC和叶片成熟度进行数量性状位点（QTL）定位。2018年，检测到3个早疫病QTL；其中两个位于5号染色体上，与成熟度QTL重叠，另一个位于7号染色体上，与成熟度QTL独立。2019年，检测到6个早疫病QTL；5号染色体上的两个QTL与成熟度QTL重叠，另外4个QTL与成熟度QTL不重叠。这些QTL的鉴定为早疫病抗性的遗传基础提供了新的见解，并可能作为早疫病抗性育种中标记辅助选择的来源。
