EFFECT OF CYTOKININS ON THE DISEASE RESISTANCE OF TOMATO CULTIVARS TO THE INFECTION OF TOBACCO MOSAIC VIRUS (TMV-T)

The present paper deals with the different effects of the endogenous cytokinins, namely, those of lower R_1 values (L-CTKs) (R_f=0.0—0.5) and those of higher R_1 values (H-CTKs) (R_f=0.5—1.0) on the disease resistance and symptom expression of tomato plants after infection by TMV-T. After the infection of TMV-T, H-CTKs in susceptible tomato cultivars were increased markedly, but not in the resistant cultivars. However, the level of L-CTKs was much higher in resistant cvs than in susceptible ones. Such difference was considered to be used as one of the criteria for the preliminary determination of disease resistance of tomato plants to TMV-T. The application of prepared H-CTKs onto the healthy tomato leaves induced a series of symptoms, including "green islands", while the application of TMV tolerance inducer NS-83 caused a raise of the level of L-CTKs to that of resistant cnltivars. It is, therefore, inferred that L-CTKs might be indirectly related to the resistant genes, while H-CTKs to the genes con     

细胞分裂素(CTK_s)在感染烟草花叶病毒番茄株系(TMV-T)的番茄品种中对抗病性的作用

本文报道番茄内源低Rf值(L-CTK_s)和高Rf值(H-CTK_s)CTK_s在抗病性和症状表现中显示不同的作用。TMV-T侵染以后,感病品种中CTK_s明显增加,特别是H-CTK_s;抗病品种无明显变化。抗病品种中L-CTK_s活性比感病品种中高,这种差别可能用以作为初步确定番茄对TMV-T抗病性的标准之一。外用H-CTK_s在健株上可诱致绿岛等症状;外用耐病毒诱导剂NS-83可增加感病品种中的L-CTK_s,使接近抗病品种的水平。因此推断认为L-CTKs可能与抗病基因间接有关,而H-CTK_s可能与控制症状表现的基因间接有关,这种机理有待进一步研究。