长豇豆抗枯萎病的遗传

两个抗镰刀菌枯萎病(Fusarium oxysporum Schl.f.sp.tracheiphilum)的长豇豆品种“猪肠豆”和“珠燕”分别与感病品种“红嘴燕”及“四季青”进行正、反杂交及回交。用分离自广州地区的5个长豇豆枯萎病菌株的混合孢子液进行苗期人工接种鉴定,测定亲本F_1、F_2及回交群体的抗病性。遗传分析的结果表明:“猪肠豆”与“珠燕”这两个抗源品种对枯萎病的抗性均受一个显性基因控制。

INHERITANCE OF RESISTANCE TO FUSARIUM WILT IN YARDLONG BEAN [VIGNA SESQUIPEDALIS (L.) FRUHW]

The objective of this study was to determine the mode of inheritance of resistance to Fusarium wilt (Fusarium oxysporum f. sp. trancheiphlum) in yardlong bean (Vigna sesqupedalis (L) Fruhw. ) .Two Fusarium wilt resistant cultivars of yardlong bean, 'Zhuchang Dou' and 'Zhu Yan', were crossed in turn with two susceptible cultivars, 'Hong Zui Yan' and 'SI Gi Ching'. The F, generations of the crosses all showed resistance to the disease as identified by the inoculation with mixed spores of 5 isolates of F.oxysporum f .sp .tranchei-p'il'um that were collectel in the region of Guangzhou. Progeny of the F2 generations of all the corosses segregated in the ratio of 3 : 1 (resistant t suscepsible) , indicating that resistance is governed by a single dominant gene. The same ratio could be obtained whether a resistant cultivar or a susceptible cultivar was used as the maternal parent in the crosses, when theF, plants were backcrossed to the susceptible parents, the BC 1 population segregated in the ratio of 1 t 1 (resistant : susceptible) , but when they were backcrossed to the resistant parents, the BC 1 generations were entirely resistant. The results as shown by the F1 , F2 and the BC 1 generations demostrated that the resistance of 'Zhu Chang Dou' and 'Zhu Yan' to Fusarium wilt was governed respectively by one dominant gene.