【摘要】 1983年用四川的117个小麦白粉菌株在 Festival(Pml),白免3号(Pm2x)、Khapli(Pm4)、Redman(Pm5)、高加索(Pm8)、洛夫林10号,肯贵阿和81夏—5118个监测品种上测得毒力频率:V1为93.2%、V2 14.5%、V40%、V5 97.4%、V8 70.1%、洛夫林10号、肯贵阿和81夏—511上依次为59.0%、11.1%和1.7%。又利用毒力公式的形式,展示出在白免3号、高加索、肯贵阿和81夏—511 4个抗源品种上,小麦白粉菌株所出现的抗、感组合频率。在小麦白粉菌毒力监测的基础上,1983—1984年又用多菌株在田间混合接种,测定32个品种的平均侵染系数(ACI)。携有抗性基因 Pm2、Pm4和 Pm2+6的品种 Maris Templar、Yuma、CI12633等,和肯贵阿、81夏—511、81—7241品种的ACI 均极低,发病轻微。而携有抗性基因 Pm1、Pm5、Pm1+2的品种穗期的AGI 偏高。含有白免3号和高加索血缘的品种,如黔花1、3、4号和黔丰4号,是高度抗病的。而单独含有高加索或洛夫林10号等血缘的品种,感病均较严重,这在综抗矮2号、C123、775—1,Alondra“S”、Bobwhite“S”、Veery“S”等品种上高的 ACI 数值,可以反映出来。试验表明,病菌毒力频率高或中等的,相应品种的 ACI 多半也高,频率低的 ACI 也偏低的趋势,但也有个别品种例外。可以认为,毒力监测结果,可实用于推测品种田间抗、感的表现。本文还就小麦白粉菌毒力监测在使用上的问题进行了讨论。更多还原

【Abstract】 A set of monitors including Festival（Pm_）,Baimian 3(Pm_2x),Khapli（Pm₄）,Redman（Pm₅）,Kavkaz（Pm_）,Lovrin 10,Ken-Gui-Aand 81 Xia-511 were inoculated respectively with 117 isolates of Erysiphegraminis f.sp.tritci from Sichuan in 1983.The virulence frequencies offungus were as follows:V being 93.2%,V₂ 14.5% V₄ 0%,V,97.4%,V 70.1% and 59.0% on Lovrin 10,11.1% on Ken-Gui-A and 1.7% on 81Xia-511.By using the virulence formula,the frequencies of resistant orsusceptible combination on the Baimian 3,Kavkaz,Ken-Gui-A and 81Xia-511 were shown.On the basis of the virulence monitoring,several isolates were ino-culated mixedly on the tested cultivars during 1983—1984,and an averagecoefficient of infection（ACI）was calculated from 32 related cultivarsand the susceptible control.The results showed that on Maris Templar,Yuma and CI 12633 etc,carrying the gene（s）Pm₂,Pm₄,and Pm₍2+.respe-ctively,and Ken-Gui-A,81Xia-511 and 81-7241 etc,the ACI values weresmall,while on cutivars carrying the gene（s）Pm_,Pm_,and Pm₁₊₂,ACIvalues were greater.The progenies from the crosses involving Baimian 3and Kavkaz,for example,Qianhua 1,3,4 and Qianfeng 4 were highlyresistant,but cultivars carrying the resistant of Kavkaz（Pm_）orLovrin 10 alone,such as C123,Zeng-kang-A 12,775-1,Alondra “s”,Bobwhite“s”and Veery“s”were highly susceptible.The results indicated that if the virulence frequency of the mildewwas high or moderate,the ACI value of the corresponding cultivars alsotended to increase.On the contrary,ACI tended to decrease when thefrequency was low,though a few cultivars were exceptional.Finally,theresults suggest that the result of virulence monitoring can be applied topredict wheat cultivar resistance to mildew,expressed in the field.In this paper the problems in relation to the use of virulence freque-ncy were also discussed.更多还原