Summary: | 碩士 === 臺灣大學 === 園藝學研究所 === 98 === High temperature has negative effects of tomato (Lycopersicon esculentum. Mill) production. Heat tolerant tomato cultivars are needed in summer Taiwan. But the saline soil problem is getting more and more serious in the main habitat. The salt tolerance of the Taiwan-bred heat-tolerant cultivars was not well research. And the different stress could happen at the same time in the nature. It’s also unclear about the tomato growth and development under double stress of heat and salt. To document the effects of salt and salt with high temperature to the plant growth, fruit yield and quality of three different levels heat-tolerant tomato cultivars, ‘Tainan ASVEG No.19’, ‘Hualien ASVEG No.21’ and ‘Taiwan seed ASVEG No.22’ were grown in the pot and treated with four levels sodium chloride (NaCl) solution for 20 days at fruiting phase under Summer 2009 and Fall 2009 respectively.
Under optimal temperature, leaf number, leaf area, fresh weight per fruit, yield, shoot and total dry weight decreased with NaCl treated. But fruit dry matter (%), total soluble solid (oBrix) and titratable acidity (%) increased. And other parameters were not affected by the treatments. ‘Taiwan seed ASVEG No.22’ has the largest yield but lowest vegetative growth. ‘Tainan ASVEG No.19’ was opposed. The yield was only affected by fresh weight of single fruit. Under salinity, ‘Taiwan seed ASVEG No.22’ had higher yield and ‘Hualien ASVEG No.21’ had better vegetative growth.
Under high temperature, NaCl caused decrease of most parameters. It may related to the strong osmotic stress due to the high temperature. But, root/shoot ratio, fruit dry matter (%), total soluble solids and unmarketable fruit (%) increased. ‘Tainan ASVEG No.19’ had low vegetative growth but the highest fruit set (%), fruit number and yield. ‘Hualien ASVEG No.21’ was opposed. ‘Hualien ASVEG No.21’ had better vegetative growth.
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