成株期叶锈病侵染对大麦植物光合作用和产量的影响

 应用¹⁴C同位素示踪分析法研究叶锈病(Puccinia hordei)在花期后(GS71)侵染对大麦植物光合作用的影响,结果表明,给叶片接菌后0至8天内无明显的光合病变,8天之后叶片的总光合量下降而单位绿叶面积光合效率提高,且这种下降%和提高%分别与锈病严重度呈显著的直线相关(r² ≥ 0.980,P<0.001);植株上单叶发病后其它器官的光合作用略有增强,全株叶片发病后穗部光合作用的增加达到显著水平(P<0.05)。
叶锈病在抽穗期(GS55)侵染后,植株籽粒产量和千粒重减低(P<0.01),而病叶干物重则显著增高(P<0.01),本文分析讨论了这些变化的生理机制。

INFLUENCE OF INFECTION BY PUCCINIA HORDE. ON YIELD AND PHOTOSYNTHESIS IN MATURE PLANTS OF BARLEY

The effect of postanthesis infection by Puccinia hordei on photosynthesis in barley was investigated with greenhouse potgrown plants, using ¹⁴C tracer method.Photosynthesis was not significantly altered until the 8th day following rust inoculation (beginning of sporulation), but henceforth marked changes were observed when rust was fully developed:total photosynthesis was much reduced whereas the photosynthetic rate of green leaf area was considerably enhanced.Regression analysis showed that the reduction(%) and the enhancement (%)were linearly correlated, respectively,with rust severity measured as percent leaf area infected(r² ≥ 0.980, P<0.001).Photosynthesis in the healthy organs of single-leaf rusted plant was slightly stimulated whilst that in the ears of plants with all leaves diseased was significantly increased (p<0.05) fourteen days after inoculation.
Leaf rust infection late in plant development (GS55) markedly decreased grain yield per ear and 1000-grain weight.These decreases could be attributed primarily to the reduced photosynthesis and other rust-induced alterations in the affected leaves of the plants.