牛番茄於高溫環境節水處理下葉片氣孔導度與鈣在植體分布間之相關性研究

Study on the relationship between leaf stomatal conductance and calcium distribution of beef tomato plants with water saving treatment in high temperature environment

本研究調查牛番茄於高溫下當介質含水量低時之葉片氣孔導度及植體中鈣含量，並分析其與果實尻腐病發生之關係。‘和生743’及‘全福994’牛番茄植株進入生殖生長後，進行節水處理(Field Capacity, FC 40%)。於高溫時段，兩品種第三及第四花序旁葉片之氣孔導度減弱、葉溫上升，較高節位葉片之鈣含量皆顯著減少，葉溫與氣孔導度間具有負相關性，葉片鈣含量與葉片氣孔導度之間則呈正相關性。節水處理下‘和生743’較高節位果實之果頂部鈣含量顯著減少，尻腐病發生率亦顯著高於‘全福994’。植體水分指數(Water Index, WI)隨介質水分含量減少呈遞減趨勢，二者之間並具高相關性。本試驗結果顯示，透過葉溫與葉片光譜儀器監測牛番茄葉片之溫度變化，可為高溫情形下栽培介質水分變化及果實尻腐病發生之指標。

The aim of this study is to investigate the leaf stomatal conductance and calcium contents in the plants on the incidence of blossom-end rot of beef tomato grown in high temperature. Beef tomatoes‘TMB-743’and‘ChenFu 994’were grown under water-saving treatment, i.e. 40% field capacity, during reproductive stage. For the leaves close to the third and fourth trusses in both cultivars in hot season, the stomatal conductances were reduced, leaf temperatures raised, and the leaf calcium contents significantly decreased. There were negative correlation between leaf temperature and leaf stomatal conductance, and positive correlation between leaf calcium content and leaf stomatal conductance. In the higher trusses of water-saving treated‘TMB-743’, the calcium content in fruit distal part was significantly decreased and the incidence of blossom-end rot (BER) significantly higher than‘TMB-743’fruits. Water Index (WI) of plant showed the reduced trend highly correlated with the decreased water content in the cultural substrate. The results showed that the leaf temperatures monitored by leaf spectrometer could be an indicator for water content changes in the cultural substrate and the incidence of blossom-end rot of beef tomato during high temperature condition.