花生黑腐病抗病品种筛选及抗病相关酶活性测定

花生黑腐病是由冬青丽赤壳(Calonectria ilicicola)引起的花生毁灭性病害。为研究花生品种对该病害的抗性情况和抗性机制,采用幼芽水培接种的方法对128个花生品种进行抗性鉴定。结果发现高抗、中抗、中感、高感的花生品种数分别为1、13、42和72个。高抗品种T09的病情指数仅为8.0,发病率为36.7%;高感品种P562的病情指数高达46.0,发病率为100%。通过室内盆栽试验方法对P562、桂花35、云花生、AS09和T09进行抗病性检验,结果与幼芽水培接种鉴定的结果一致。通过测定T09和P562接种花生黑腐病菌后防卫相关酶活性的变化,T09的苯丙氨酸解氨酶(PAL)活性分别在接种后0.5和5 d出现2次高峰(最大峰值为451.09 U·g^-1·h^-1FW),其峰值出现时间较高感品种P562早;T09的多酚氧化酶(PPO)活性在接种后0.5 d出现峰值(271.67 U·g^-1·min^-1FW),P562的PPO活性在接种后1 d出现峰值(160.02 U·g^-1·min^-1FW);两个品种的过氧化物酶(POD)活性均升高,T09在接种后0.5 d出现高峰(239.23 U·g^-1·min^-1FW),P562在接种后0.25 d出现高峰(135.75 U·g^-1·min^-1FW);两个品种接种后超氧化物歧化酶(SOD)活性均升高,T09在接种后的第5天出现高峰(28.08 U·g^-1·h^-1FW),P562在接种后第3天出现高峰(16.79 U·g^-1·h^-1FW)。酶活性结果表明,PAL、PPO、POD和SOD在花生抗病性中可能密切相关。本研究结果为后续花生高抗品种的选育及花生黑腐病的抗病机制奠定了基础。

Screening of Peanut Black Rot Disease-Resistant Varieties and Determination of Defense-Related Enzyme Activities

Peanut black rot, caused by Calonectria ilicicola, is one of the most important diseases that causes the greatest reduction in peanut yield worldwide. To understand the resistance and mechanism of peanut varieties to the disease, 128 peanut cultivars were collected and tested for their resistance to peanut black rot disease by artificial inoculation. The results showed that there were 0, 1, 13, 42 and 72 varieties showing immunity, high resistance, medium resistance, medium sensitivity and high sensitivity to peanut black rot respectively, accounting for 0, 0.8, 10.2, 33.7 and 56.3% of the tested peanut varieties. T09 had the lowest disease index of 8, the incidence rate was 36.7%, while the disease index of P562 was the highest wiht 46, and the incidence rate was 100%. Further, the pot experiments of P562, Guihua 35, yunpeanut, AS09 and T09 were carried out by the method of inoculation with oat grains mixed with soil. The results showed that T09 was the most resistant and P562 was the most susceptible, which was consistent with the results of hydroponics method. Two peaks (with 451.09 U·g^-1·h^-1FW peak value) of PAL appeared at 0.5 d and 5 d after inoculation, respectively. The peak PAL of T09 was earlier than that of P562. The PPO peak of T09 was 271.67 U·g^-1·min^-1FW at 0.5 d after inoculation, while P562 had 160.02 U·g^-1·min^-1FW at 1 d after inoculation. The POD of T09 peaked at 0.5 d after inoculation with a maximum value of 239.23 U·g^-1·min^-1FW, while the P562 peaked at 0.25 d after inoculation with a maximum value of 135.75 U·g^-1·min^-1FW. The SOD of both cultivars increased after inoculation. The SOD of T09 peaked at 5 d after inoculation with the maximum value of 28.08 U·g^-1·h^-1FW, while that of P562 was 16.79 U·g^-1·h^-1FW at 3 d after inoculation. The results of enzyme activity showed that PAL, PPO, POD and SOD may related to peanut disease resistance. This study laid a foundation for the selection of high resistant peanut varieties and the further research about the resistance mechanism to peanut black rot.