茶鲜叶可溶性糖和氨基酸含量与低温的相关性

为评价茶树抗冻物质基础和品种间抗冻性差异,选择乌牛早和茂绿品种的栽培茶园,从2013年10月20日到翌年4月5日逐日调查供园气温;每月5、15、25日采集茶树成叶,以比色法检测鲜叶可溶性糖含量,以HPLC检测脯氨酸等17种游离氨基酸含量。结果发现:1在2013年10月20日至12月27日气温持续下降、2013年12月28日至翌年2月10日持续低温、2014年2月11日至4月5日气温日渐升高的3个时段,可溶性糖含量相应地持续增加、继续增加、逐渐减少,整个试验期间温度与可溶性糖含量显著负相关;2脯氨酸含量和17种游离氨基酸总量在这3个阶段相应的缓慢增加、明显增加、显著提升。研究结果表明:1可溶性糖、脯氨酸、游离氨基酸,这3类都是茶树抗寒物质,且可溶性糖含量与温度相关性大于其他两类物质;2这3类抗冻物质的含量,乌牛早鲜叶相应地大于茂绿鲜叶,乌牛早冻害指数小于茂绿冻害指数,因此乌牛早抗冻性更强。

Correlation of Low Temperature with Soluble Sugar and Amino Acid Content in Fresh Tea Leaves

In order to evaluate the substantial basis of tea plant resisting frost as well as the difference in frost resistance of different cultivars,thetea plantation growing with cultivar Wuniuzao and another plantation growing with Maolüwereselected, in which the temperatute was recorded day by day. At the fifth, the fifteenth and the twenty fifth of each month during the experimental duration, the fresh tea leaveswere plucked, in which thesoluble sugar contentwas detected by colourimetry, and the prolinecontentand seventeenfree amino acid contentswere determined by HPLC. The results showed that:①Within the three durations the temperature dropped continually (from October 20 to December 27 in 2013), the low temperature lasted (from December 28 to February 20), and the temperature rose gradually,accordingly, the soluble sugar content continually raised, and keeped on increasing, then reduced insignificantly,furthermore,the soluble sugar content negatively correlated with temperature in the whole experimental stage.②Accordingly, theproline contentand the seventeenfree amino acid contentslowlyraised, and obviously increased, then markedly promoted. It was considered that:①The three types of substances were allrelated to the resisitance on cold injury, and the correlation of thesoluble sugar contentwith lowtemperature was larger than those of other two types ofsubstances with the temperature.②The content of thesethree types of cold-resisting substances in cultivar Wuniuzao was more than thosein Maolü,at the same time, the frezzing injury index of Wuniuzao wasless than that of Maolü, therefore, the Wuniuzao possessed even strong resistance against freezing.