International Centre of Insect Physiology and Ecology, Based on IRRI, P. O. Box 30772, Nairobi, Kenya.
J Chem Ecol. 1991 Jan;17(1):41-65. doi: 10.1007/BF00994421.
A wild rice,Oryza brachyantha, was rated as highly resistant to rice leaffolder,Cnaphalocrocis medinalis (Guenée), while its F1 hybrid from a cross with a high-yielding, leaffolder-susceptible rice, IR31917-45-3-2, was rated resistant in a standard screening test. In comparison with IR31917-45-3-2,O. brachyantha and the F1 hybrid were unsuitable for oviposition, survival, and growth ofC. medinalis. However, growth and survival of larvae in artificial diets containing lyophilized leaf powder of IR31917-45-3-2 andO. brachyantha were comparable. Studies on the feeding and settling preference of the larval stages suggested that the mechanism of resistance ofO. brachyantha is that of antixenosis type. Olfactometer tests with first-instar larvae and electroantennogram responses of adults indicated a lack or low levels of volatile attractants inO. brachyantha and the F1 hybrid in comparison with IR31917-45-3-2. Bioassays of sequential solvent extracts of these plants indicated that larval preference for IR31917-45-3-2 and nonpreference forO. brachyantha and the F1 hybrid were due partly to chemical factors present in hexane and methylene chloride extractables. Closer arrangement of silica cells in the epidermal layer ofO. brachyantha and a higher mandibular wear in larvae reared onO. brachyantha suggested that physical resistance due to silica may be an additional cause of resistance. It was hypothesized that the high levels of resistance observed inO. brachyantha may be due to an additive or synergistic action of the absence of attractants or feeding stimulants, the presence of deterrents, and the physical resistance offered by silica. The significance of these results to a successful wide hybridization program aimed at transferring resistance factors from wild rice to cultivated rice is discussed.
一种野生稻，Oryza brachyantha，被评价为对稻纵卷叶螟，Cnaphalocrocis medinalis（Guenée）高度抗性，而其与高产、易受稻纵卷叶螟侵害的水稻品种 IR31917-45-3-2 的杂交 F1 代在标准筛选试验中被评价为抗性。与 IR31917-45-3-2 相比，O. brachyantha 和 F1 代杂种不适合稻纵卷叶螟产卵、生存和生长。然而，在含有 IR31917-45-3-2 和 O. brachyantha 冻干叶粉的人工饲料中，幼虫的生长和存活率相当。对幼虫阶段取食和定殖偏好的研究表明，O. brachyantha 的抗性机制是抗生性类型。用初孵幼虫的嗅觉计试验和成虫的触角电位反应表明，与 IR31917-45-3-2 相比，O. brachyantha 和 F1 代杂种缺乏或低水平的挥发性引诱剂。这些植物的连续溶剂提取物的生物测定表明，幼虫对 IR31917-45-3-2 的偏好和对 O. brachyantha 和 F1 代杂种的非偏好部分归因于正己烷和二氯甲烷可提取物中存在的化学因素。O. brachyantha 表皮层中硅细胞的更紧密排列以及在 O. brachyantha 上饲养的幼虫的下颌磨损更高，表明由于硅的物理抗性可能是抗性的另一个原因。据推测，在 O. brachyantha 中观察到的高水平抗性可能是由于缺乏引诱剂或摄食刺激物、存在驱避剂以及硅提供的物理抗性的累加或协同作用所致。讨论了这些结果对旨在从野生稻向栽培稻转移抗性因子的成功广泛杂交计划的意义。
