土壤干旱对小粒种咖啡有关生理参数的影响

Effect of drying Soil on Relevant Physiological Parameters of Coffea Arabica

对塑料袋一年生咖啡苗定期停止淋水，使土壤遭受不断加剧的干旱胁迫，以检测水分供应对咖啡生理状况的影响。试验结果表明：轻度水分胁迫，如１ｄ不淋水，即导致咖啡光合速率、蒸腾速率、可溶性蛋白质和叶绿素、类胡萝卜素含量以及含水量、气孔开张率、水势等生理参数开始下降；而过氧化物酶活性、脯氨酸和丙二醛含量以及细胞透性等生理参数开始上升，且随土壤水分胁迫的逐步加剧，上述各生理参数呈渐进性恶变。光合速率对土壤水分的反应属敏感参数之一，轻度干旱即使光合速率明显下降。高温间歇干旱期，常规管理的田间含水量能使咖啡光合速率受到抑制，灌水可促使光合速率提高。

One year old Coffea arabica seedlings raised in plastic bags were treated with increas-ing water stress to study effects of water supply on physiologic status, Results showed that slightstress,such as by withholding water supply only one day,led to a decrease in photosynthesisrate, transpiration rate,soluble protein content, chlorophyll and carotenoid content,water con-tent, ratio of opening stomatas and leaf water potential,and an increase in peroxidase activity,contents of proline and malondialdehyde, and permeability of cell membranes. These foregoingphysiological parameters were changed gradually with increased soil water stress, Photosynthesisrate was a more sensitive parameter to soil water content and a slight water stress gave rise to asignificant decline in photosynthesis rate. In the warm and dry season, the low field water con-tent under regular management inhibited photosynthesis rate which could be increased by irriga-tion.