ABSTRACT

Fusarium wilt (FW), caused by Fusarium oxysporum Schlechtend f. sp. melonis (Leach & Currence) Snyd. & Hans (Fom) is a substantial threat to muskmelon (Cucumis meloL.) cultivation around the world. Identification of new sources of resistance and transfer of the resistance genes to elite cultivars is the effective breeding strategy to reduce the FW-associated crop losses in muskmelon. In the present study, inheritance studies and molecular mapping for FW resistance were conducted in a muskmelon inbred line KP₄HM-15 with FW resistance introgressed from snapmelon. Inheritance studies in the F₂ population derived from the cross Punjab Sunehri//KP₄HM-15 indicated that FW resistance in KP₄HM-15 is governed by a single dominant gene. Bulked segregant analysis was conducted to map the Fom-5^(t) gene in KP₄HM-15 using 527 SSR primers. Four primer pairs, CMCTN35, DM0096, CSWCTT02, and ECM181, were found to show differential polymorphism in the resistant and susceptible bulks and were analysed in the whole of the population. Two SSR markers, DM0096 and CSWCTT02, mapped close to the Fom-5^(t) gene at a genetic distance of 1.4 and 2.5 cM, respectively. These markers can potentially be used to transfer Fom-5^(t) in elite muskmelon genotypes through marker-assisted backcross breeding until more tightly linked markers are available.

摘要

Fusarium wilt (FW)，由Fusarium oxysporum Schlechtend f 引起。sp。melonis (Leach & Currence) Snyd。& Hans ( Fom )对世界各地的甜瓜 ( Cucumis melo L.) 种植构成重大威胁。鉴定新的抗性来源并将抗性基因转移到优良品种是减少甜瓜与FW相关的作物损失的有效育种策略。在本研究中，在甜瓜自交系 KP ₄ HM-15 中进行了 FW 抗性的遗传研究和分子作图，该甜瓜抗性从 snapmelon 渗入。来自交叉旁遮普 Sunehri // KP _{4的 F 2}群体的遗传研究HM-15 表明 KP ₄ HM-15 中的 FW 抗性受单个显性基因控制。使用 527 个 SSR 引物进行批量分离分析以绘制KP _{4 HM-15 中的}Fom-5 ^(t)基因。发现四个引物对 CMCTN35、DM0096、CSWCTT02 和 ECM181 在抗性和易感群体中显示出差异多态性，并在整个群体中进行了分析。两个 SSR 标记 DM0096 和 CSWCTT02分别以 1.4 和 2.5 cM 的遗传距离定位到靠近Fom-5 ^{(t)基因的位置。}这些标记可用于转移Fom-5 ^(t)通过标记辅助回交育种在优良甜瓜基因型中进行，直到获得更紧密连锁的标记。