遮荫对休眠期大樱桃芽呼吸代谢的影响研究

Effects of shading on the respiration metabolism of cherry buds in dormant period.

试验研究遮荫处理对休眠期大樱桃花芽、叶芽呼吸代谢的影响结果表明 ,休眠前期大樱桃花芽和叶芽呼吸强度均较弱 ,先期缓慢下降且叶芽降幅低于花芽 ,低温来临后其呼吸强度有较大幅度下降 ,之后变化较小 ;休眠末期其呼吸强度缓慢上升。自然条件下 3条主要呼吸途径变化趋势不同 ,糖酵解途径呈下降趋势 ,三羧酸循环途径始终徘徊在 4 8%左右 ,磷酸戊糖途径则呈明显上升趋势。磷酸戊糖途径不断得到活化 ,推测其增强可能是解除大樱桃休眠的主要原因 ,这与打破种子休眠的研究结果一致。遮荫处理对大樱桃花芽和叶芽呼吸强度的影响趋势类似 ,即 10月 2 4日前其呼吸强度迅速下降 ,之后变化较小。遮荫处理使花芽呼吸强度降幅略大于叶芽 ,且遮荫程度对其影响也大于叶芽。遮荫处理对花芽和叶芽呼吸途径的影响一致 ,与对照相比遮荫处理使糖酵解途径所占比率降低 ,三羧酸循环途径比率略有增加而磷酸戊糖途径比率显著上升 ;2层遮荫处理糖酵解途径降幅和磷酸戊糖途径增幅均大于 1层遮荫处理。遮荫处理使磷酸戊糖途径不断增强 ,表明遮荫处理可能是通过呼吸代谢而促进大樱桃芽休眠的解除。

The effects of shading on the respiration metabolism o f flower buds and leaf buds of cherry in dormant period were studied. The results show that in early dormant period the respiratory intensities of cherry flowere d buds and leaf buds are relatively infirm and reduce slowly and the slowdown of leaf buds is lower than that of flower buds. At the lower temperature the resp ir atory intensities rapidly decline and after that they change little. In the late dormant period the respiratory intensities slowly rise.Under the nature condi tion three respiratory pathways show different changes: EMP reduces and TCA alwa ys fluctuates at about 48 percent,but PPP markedly rises. This shows that PPP may be the main reason of dormant relieve,this is in accord with the study of seed. Effects of shading on the respiratory intensities of flower buds and leaf buds a re consistent:before October 24,they rapidly reduce and then change little.Flowe r buds reduce more rapidly than leaf buds and different shadings affect it bigge r than the latter.Effects of shading on the respiratory pathways of flower buds are similar to those of leaf buds,the shading makes EMP reduce but TCA and PPP r ise. The slowdown of EMP and the increase -rang e of PPP of two -layer shading are bi gger than those of one -layer shading. The shad ing makes the PPP continuously enhanced, indicating that shading through PPP may promote the release of bud dormancy.