桃蚜誘導杏幼葉局部細胞超微結(jié)構(gòu)退化

摘 要： 蚜蟲是以植物韌皮部汁液為食的專性寄生昆蟲，杏樹春生新梢易受桃蚜等蚜蟲侵染，桃蚜在新梢上迅速繁殖并聚集，汲取韌皮部富含糖分的汁液，通常引起杏葉卷曲變形，抑制新梢生長。為了解桃蚜侵染對杏幼葉超微結(jié)構(gòu)產(chǎn)生的影響，以采集被蚜蟲寄生的幼葉，經(jīng)過固定、脫水和包埋，做成厚度60 nm超薄切片，采用透射電子顯微鏡進行觀察。結(jié)果表明，受桃蚜侵染幼葉中有少數(shù)細胞表現(xiàn)超微結(jié)構(gòu)變化：細胞過度液泡化以致液泡占據(jù)了細胞絕大部分內(nèi)部空間，同時，細胞質(zhì)過度降解，細胞器減少，細胞核收縮，核質(zhì)中均勻地積累嗜鋨性細顆粒物質(zhì)致使細胞核電子染色加深，染色質(zhì)顆粒消失，細胞壁增生導致細胞變形。根據(jù)觀察結(jié)果得出結(jié)論，桃蚜侵染杏幼葉能引起幼葉局部細胞發(fā)生超微結(jié)構(gòu)退化。

關(guān)鍵詞： 杏； 桃蚜； 葉； 超微結(jié)構(gòu)

中圖分類號：Ｓ６６2．1 文獻標識碼：Ａ 文章編號：１００９－９９８０?穴２０11?雪０6－1050－０4

Ultrastructural degeneration of part cells in young leaves of apricot caused by green peach aphids

LIU Lin

（College of Life Sciences， Linyi University， Linyi， Shandong 276005 China）

Abstract: Aphids are plant phloem-feeding insect， sucking the sugary liquids from the host plant’s vascular system. Green peach aphids （Myzus persicae） often infest the emerging shoots of apricot （Prunus armeniaca Linn.）. The aphids reproduce rapidly and cause severe distortion of young leaves and inhibit the growth of the new shoots. In order to characterize the ultrastructure alterations in the infested young leaves， leaf samples were examined by means of transmission electron microscopy. Most cells in the infested young leaves were moderately vacuolated and appeared healthy， but there were a small number of cells that showed excessive vacuolation and cytoplasmic reduction. In the excessively vacuolated cell， a large vacuole occupied almost all the cell’s total volume， whereas cytoplasm was reduced to very little. The excessive cytoplasmic reduction was concomitant with nucleus deterioration. The nucleus deterioration was symptomized as nucleus shrinkage， extensive accumulation of diffusible osmiophilic compounds， and disappearance of chromatin granules. The excessive cytoplasmic reduction and the concomitant nucleus deterioration led to the subsequent cell distortion. Results suggested that the infestation of green peach aphids caused ultrastructural degeneration to a limited number of cells in the infested young leaves of apricot.

Key words: Prunus armeniaca； Green peach aphid； Leaf； Ultrastructure

蚜蟲是以植物韌皮部汁液為食的專性寄生昆蟲，具舐食習性，將一根長而具韌性的口針插入植物組織并進行化學分析以確定植物是否可食和尋找韌皮部位置[1]。口針一般沿著細胞初生壁和次生壁之間的質(zhì)外體途徑行進[2]，途中不停地分泌凝膠型唾液，形成包圍口針的唾液鞘，唾液鞘具有一定硬度，并具潤滑功能，便于口針進退[3]。口針在行進途中不斷迅速穿刺細胞，將少量水溶型唾液注入細胞內(nèi)，然后攝取微量唾液和細胞質(zhì)的混合液以對細胞進行化學分析[4]。……