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体外和活体研究表明,从病叶获得的橡胶树粉孢的分生孢子大部分都不发芽,除非通过震动除掉垂死的孢子。24时龄的分生孢子的发芽率最高。分生孢子在5—35℃之间都发芽,在25—30℃发芽率最高,在40℃受到完全抑制。撒在叶上的分生孢子其发芽和侵染有相似的模式。在相当大的湿度范围内都能发芽,但良好的侵染需要高湿。在高温下培育的孢子,在饱和湿度下发芽较好。干燥显著降低孢子的生活力。在呈雾状自由水的载玻片和叶面上分生孢子发芽和生长都良好。但是长时间浸沉在水中抑制发芽。在人工光照下比在黑暗下发芽更好。直射阳光和紫外光对孢子发芽有害,离体的孢子比附在叶上的孢子受害更明显。当用橡胶树粉孢的分生孢子接种对白粉病具有不同感病性的橡胶品系的9日龄叶片时,接种后6小时在感病品系和耐病品系上都看到吸附胞。耐病品系的分生孢子粳数目比感病品系的显著较少。在耐病品系的侵入点周围看到一种过敏性反应。组织病理学研究表明表皮细胞内的原生质内容被分解了。在颗粒状表皮细胞内含物中有时看到败育的吸器,但在大多数情况下未见败育吸器。在耐病品系受害表皮细胞下的栅栏细胞似乎受到不利的影响。讨论了气象参数对橡胶树粉孢发育的影响和橡胶品系对侵染的反应,及白粉病的流行病学和防治。
In vitro and in vivo studies have shown that most of the conidia from the diseased leaves do not germinate unless the dying spores are removed by shaking. 24-year-old conidia germination rate is highest. Conidia sprouted between 5-35 ° C with the highest germination rate at 25-30 ° C and complete inhibition at 40 ° C. Spore on the leaves of conidia germination and infection have a similar pattern. Germinate over a wide range of humidity, but good infestation requires high humidity. Spores incubated at high temperature are better at germination under saturated humidity. Drying significantly reduces spore viability. Conidia sprouted and grew well on glass slides and foliar leaves in the form of mist. But prolonged immersion in the water to inhibit germination. It is better to germinate under artificial light than under darkness. Direct sunlight and ultraviolet light are harmful to spore germination, and spores in vitro are more affected than spores attached to leaves. When the 9-day-old leaves of the rubber strain having different susceptibilities to powdery mildew were inoculated with conidia of Asteraceae gum, adsorbent cells were seen on susceptible and resistant lines 6 hours after inoculation. The tolerant lines had significantly fewer conidial japonica varieties than the susceptible lines. An allergic reaction is seen around the entry point of the resistant line. Histopathological studies have shown that the content of the protoplasm within the epidermal cells is broken down. Aborted inhalers are sometimes seen in granular epidermal cell inclusions, but in most cases no abortion inhalers have been found. Fence cells under the damaged epidermal cells of tolerant lines appear to be adversely affected. The effects of meteorological parameters on the development of Alternanthera philoxeroides, the response of rubber strains to infection and the epidemiology and control of powdery mildew were discussed.