Lahari Zobaida, Ribeiro Antonio, Talukdar Partha, Martin Brennan, Heidari Zeynab, Gheysen Godelieve, Price Adam H, Shrestha Roshi
1Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
3Centre for Genome-Enabled Biology and Medicine, University of Aberdeen, Aberdeen, UK.
Euphytica. 2019;215(7):117. doi: 10.1007/s10681-019-2427-0. Epub 2019 Jun 14.
The root-knot nematode is a serious pest in rice affecting production in many rice growing areas. Natural host resistance is an attractive control strategy because the speed of the parasite's life cycle and the broad host range it attacks make other control measures challenging. Although resistance has been found in the domesticated African rice and the wild rice species the introgression of resistance genes to Asian rice is challenging. Resistance due to a major gene in would greatly aid breeding. Recently two accessions resistant to have been identified in a screen of 332 diverse cultivars. In this study, these two resistant cultivars, LD 24 (an from Sri Lanka) and Khao Pahk Maw (an from Thailand), were crossed with a moderately susceptible cultivar, Vialone Nano (a from Italy). Approximately 175 F progeny of both populations were screened for susceptibility to infection. Between 20 and 23 individuals with highest and lowest galls per plants were pooled to make susceptible and resistant bulks which were sequenced to conduct bulked segregant analysis using the QTL-seq method. This revealed a nematode resistance locus from 23 Mbp to the bottom of rice chromosome 11 in both crosses suggesting a rare introgression of the same locus is responsible for resistance in both cultivars. While this information can be used in marker-assisted breeding, analysis of available SNP data revealed candidate loci and genes worthy of further investigation for gene identification.
根结线虫是水稻中的一种严重害虫，影响着许多水稻种植地区的产量。天然宿主抗性是一种有吸引力的控制策略，因为这种寄生虫的生命周期速度以及它所攻击的广泛宿主范围使得其他控制措施具有挑战性。尽管在非洲栽培稻和野生稻品种中已发现抗性，但将抗性基因渗入亚洲稻具有挑战性。由一个主要基因导致的抗性将极大地有助于育种。最近，在对332个不同的水稻品种进行的筛选中，鉴定出了两个对根结线虫具有抗性的种质。在本研究中，将这两个抗性品种LD 24（一个来自斯里兰卡的籼稻）和Khao Pahk Maw（一个来自泰国的粳稻）与一个中度感病品种Vialone Nano（一个来自意大利的粳稻）杂交。对两个群体的大约175个F后代进行了根结线虫感染敏感性筛选。将每株植物上虫瘿数量最多和最少的20至23个个体集中起来，形成感病和抗病混合群体，并对其进行测序，以使用QTL-seq方法进行混合分离分析。这揭示了在两个杂交组合中，水稻第11号染色体底部23兆碱基处存在一个线虫抗性位点，表明相同位点的罕见渗入导致了两个品种的抗性。虽然这些信息可用于标记辅助育种，但对可用SNP数据的分析揭示了值得进一步研究以进行基因鉴定的候选位点和基因。
