刘后伟 廖章鹏 李瑞莹 洪利鹤 李霖枫 黄标 姚小华

摘要 对湛江农垦成龄和幼龄剑麻紫色卷叶病田间调查发现，一般抗病苗与普通苗发病率为18%～33%，之间无显著差异，而高抗病苗能有效对抗紫色卷叶病（发病率近0）;列联表分析表明剑麻的抗病、发病、死亡等现象不是相互独立的随机事件，存在未知关联;根据田间剑麻种植布局，每株周围剑麻分为直接接触和非直接接触两类，调查发现直接接触生病剑麻数量水平决定了发病率高低（相关系数为0.976），每增加一株病麻，剑麻发病率提高13.6%，而非直接接触生病剑麻数对发病率的影响呈弥散状，说明直接接触传染是紫色卷叶病扩散的重要因素;无论是单块成龄或幼龄剑麻田，还是二者合并，紫色卷叶病发病率分布都存在不发病和高发病2个峰，推测存在2种以上的因子影响剑麻发病，为此提出抗病因子和非抗病因子2个因子共同决定剑麻紫色卷叶病的双因子模型，这2类因子的相互作用决定了剑麻染病、恢复、再染病、再恢复的循环，能够解释目前紫色卷叶病表现。

关键词 田间调查;紫色卷叶病;发病率;直接接触传染;传病因子

中图分类号 S-435.63  文献标识码 A

文章编号 0517-6611（2021）11-0132-07

doi：10.3969/j.issn.0517-6611.2021.11.037

開放科学（资源服务）标识码（OSID）：

Field Investigation of Sisal Purple Leaf Roll Disease and Its Disease-carried Factor Analysis

LIU Hou-wei1，LIAO Zhang-peng1，2，LI Rui-ying1 et al

（1. College of Tropical Agriculture and Forestry， Guangdong AIB Polytechnic， Guangzhou， Guangdong 511368;2.School of Life Sciences，Jiaying University，Meizhou，Guangdong 514011）

Abstract Field investigations of purple leaf curl disease of sisal in Zhanjiang，Guangdong of China revealed that the incidence rates of plants grown from common resistant seedlings or non-resistant seedlings fluctuate were between 18% and 33%， and there were no significant differences between them. The high resistant seedlings were effectively against purple leaf curl disease， the incidence rate was nearly 0. Contingency table analysis showed that disease resistance， disease incidence and death of sisal were not independent random events， but had unknown associations;according to the planting layout of sisal in the field， each plant around the sisal was divided into direct contact and non-direct contact two categories. The survey found that the number of sick sisal within direct contact sisal determined the incidence of purple leaf curl disease （correlation coefficient = 0.976， slope=13.6%）， but the influences of the number of sick sisal within non-direct contact sisal were much weak， which indicated that direct contact infection should be an important route in the spread of purple leaf curl disease. For the distribution of the incidence rate of purple leaf disease had two peaks with zero incidence and the highest incidence， it was speculated that there were more than two factors affecting the incidence. The two-factors model was proposed to explain the cycle of infection， recovery， re-infection， and re-recovery at all stages of sisals life. Therefore， we put forward the two-factors model of sisal purple leaf curl disease， which was jointly determined by the interaction of disease-resistant factors and non-disease-resistant factors. The interaction of these two kinds of factors determined the cycle of infection， recovery， re-infection and recovery of sisal hemp， and could explain the current performance of purple leaf curl disease in field.

Key words Field investigation;Purple leaf curl disease;Incidence rate;Direct contact infection;Disease-carried factor

剑麻（Agave Sisalana Perr. Ex Engelm.）紫色卷叶病由剑麻新菠萝灰粉蚧（简称为粉蚧）伤害所致[1]，但在多年反复感染粉蚧病死的老麻田长出的新苗，虽也能被粉蚧所伤，但不会出现紫色卷叶病症状（这些苗也称为抗病苗），实践发现，抗病性只能在无性繁殖的腋苗和走茎苗之间传递2～3代，且随着种植时间的延长，抗病效果会逐渐减弱，适度传染粉蚧反而可以维持这种抗病性[2-3]，这表明抗病性的获得不是剑麻遗传物质的改变，更可能是某种适应性的变化。……