2,3-丁二醇诱导下匍匐翦股颖叶片细胞结构变化及抗病相关性分析

由立枯丝核菌(Rhizoctonia solani)引起的褐斑病是匍匐翦股颖草坪最常见的病害之一,2,3-BD(2,3-butanediol)可诱导植物产生抗病反应,提高植物的抗病性。本试验采用250 μmol/L 2,3-BD诱导匍匐翦股颖对褐斑病的抗性,以石蜡切片方法通过显微观察,测定接种立枯丝核菌后匍匐翦股颖叶片细胞显微结构的变化。结果表明,接种病原菌后匍匐翦股颖病情指数第15天达到70.45%,2,3-BD诱导后病情指数显著降低至21.63%。与未诱导接菌处理相比,诱导后匍匐翦股颖叶片细胞结构排列紧密,气腔变小,有较多乳突形成,上、下表皮细胞显著增大,第7天差异最显著,分别是其1.19和1.26倍;叶肉细胞大小于第15天差异最为显著,是其1.30倍;叶绿体数量明显增加,第1、7、15天分别是未诱导接菌处理的1.25、1.20、1.24倍;维管束和导管大小在各时间段均变化不明显,但木质化程度较高,皮层组织加厚。综上所述,250 μmol/L 的2,3-BD能诱导匍匐翦股颖对褐斑病的抗性,并使细胞结构发生变化,其中叶片上、下表皮细胞、叶肉细胞大小和叶绿体数目与抗病性呈正相关性。

The correlation between cell microstructure induced by 2,3-butanediol and fungal resistance of creeping bentgrass

The brown spot caused by Rhizoctonia solani is one of the most common diseases of creeping bentgrass (Agrostis stolonifera) lawns.Application of 2,3-butanediol (2,3-BD) can induce plant disease response and improve disease resistance.In the present study,creeping bentgrass was inoculated with R.solani after treatment with 2,3-BD (250 μmol/L) and then the cell microstructure of leaves was observed using a paraffin sectioning method.It was found that the disease index of creeping bentgrass without 2,3-BD reached 70.45 ％ after 15 days from inoculation.However,the disease index of creeping bentgrass treated with 2,3-BD was significantly lower,at 21.63％ (P＜0.05).Compared to leaves of pathogen-infected plants untreated with 2,3-BD,creeping bentgrass leaves with both pathogen inoculation and 2,3-BD treatment had a closely arranged cell structure,smaller cavities,more papillae,and increased upper and lower epidermal cell size.The size increase of upper and lower epidermal cells of 2,3-BD induced plants,compared to uninduced plants,was a factor of 1.19 and 1.26 times,respectively,and was most significant on day 7 after inoculation.The mesophyll cell size increase was the most significant on the 15th day (× 1.30).The chloroplast density 1,7,and 15 days after inoculation was,respectively,1.25,1.20,and 1.24 times that of uninduced plants (P＜0.05).The size of vascular bundles and ducts did not change significantly at any time,however,the degree of lignification was higher and the cortical tissue became thicker in induced plants.In conclusion,2,3-BD can induce resistance of creeping bentgrass to brown spot disease through change in the cell structure.There was a positive correlation between the upper and lower epidermal cell size,the mesophyll cell size,and the number of chloroplasts per cell in creeping bentgrass leaves,and the disease resistance.