不同紫花苜蓿品种对异茎点霉根腐病的抗病性评价

Evaluation of resistance of different alfalfa varieties to Paraphoma root rot

紫花苜蓿异茎点霉根腐病(alfalfa Paraphoma root rot,APRR)是本研究团队发现并报道的一种世界新病害。为探究不同苜蓿品种对异茎点霉根腐病的抗病性,本研究通过蘸根接种,在测定国内外30个不同苜蓿品种接种根异茎点霉后各植株的发病率、病情指数、株高、根长、单株地上生物量和单株地下生物量等指标的基础上,采用隶属函数标准差系数赋予权重法对其抗病性进行了综合评价。D值为各品种综合评价值,D值越大,该品种抗病性越强,反之越弱。结果显示:龙威3010、巨能2号和甘农3号的综合评价值D值均>0.9,分别为0.972、0.955和0.916,表明上述3个苜蓿品种对异茎点霉根腐病(APRR)的抗性较强;而草原3号和公农1号的D值<0.2,分别为0.003和0.113,对该病的抗性差;其他品种抗病性居中。研究结果初步筛选出3个对APRR抗病性强的品种,为紫花苜蓿的生产和异茎点霉根腐病的防治提供了理论依据。

Alfalfa(Medicago sativa)Paraphoma root rot(APRR)is a disease previously unknown in the world that has been identified and reported by our research team.This study evaluated the disease resistance of 30 different alfalfa varieties to root rot caused by Paraphoma radicina.In this evaluation,the incidence rate,disease index,height,root length,and above-and belowground biomass per plant were determined for 30 different alfalfa varieties,both domestic and international,after inoculation with P.radicina through root dipping.The standard deviation coefficient allocation weighted method was used to provide a multivariate evaluation of their resistance to the disease.The D value represents the comprehensive evaluation of each variety’s disease resistance.A higher D value indicates greater resistance,while a lower D value indicates lower resistance.The study found that the M.sativa varieties Longwei 3010,MagnumⅡand Gannong No.3 had composite evaluation values(D)of 0.972,0.955,and 0.916,respectively.All three varieties showed high resistance to APRR,with D values greater than 0.9.Caoyuan No.3 and Gongnong No.1 exhibited poor disease resistance,with D values of 0.003 and 0.113,respectively,both less than 0.2.The other tested varieties had intermediate disease resistance.The study has identified three varieties with strong disease resistance to APRR,providing husbandry information for alfalfa production and the prevention and control of the disease by planting resistant varieties.