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以新疆伊犁地区的4类野生杏(野生甜仁杏1号、野生甜仁杏2号,野生苦仁杏1号、野生苦仁杏2号)为材料,研究其在干旱胁迫下渗透调节物质的积累特性。对二年生天山野杏苗进行持续80d的田间自然干旱处理过程中,每隔20d取样分析土壤相对含水量(SRWC)及叶片相对含水量(LRWC),Na+,K+和可溶性蛋白质、可溶性糖以及脯氨酸(Pro)等有机渗透调节物质含量。结果表明:浇水后第20d,15～20cm土层SRWC下降到轻度胁迫(54%)时,除野生甜仁杏2号LRWC之外,其余3种类型均维持在80%以上的水平。这时除野生苦仁杏1号K+含量有所下降外,其余3种类型K+含量均开始上升。到第60～80dSRWC降至中度和极度干旱(47%～18%)时,所有4种类型野生杏均积累Na+为渗透调节物质。而对有机渗透调节物质而言,野生杏受轻度至中度干旱胁迫时积累可溶性蛋白质,此时可溶性蛋白质的积累能力可能与其抗旱性有关,当胁迫进一步加重时,以可溶性糖为渗透调节物质。最终受极度干旱胁迫时Pro含量剧增,低LRWC者其Pro含量高,而且其含量为微克级,远低于其他渗透调节物质。因此认为,Pro不参与野生杏干旱胁迫时的渗透调节,Pro含量的剧增是植物合成蛋白质的速率低于其降解速率以及细胞受损的结果。
In this paper, four kinds of wild apricot (wild sweet-tianren apricot No.1, wild sweet apricot apricot2, wild bitter apricot No.1 and wild biting apricot2) were used as materials to study the effects of osmotic adjustment substance Accumulation characteristics. During the natural drought treatment of two-year-old wild apricot seedlings in field for 80 days, SRWC and LRWC, Na +, K + and soluble protein, soluble sugar and proline Acid (Pro) and other organic osmotic adjustment substance content. The results showed that the SRWC of 15-20 cm soil layer decreased to mild stress (54%) on the 20th and 15-20th days after watering. Except for the wild Sweet Tamarind No.2 LRWC, the other three types maintained above 80%. At this time in addition to wild bitter apricot K + 1 on the decline, the remaining three types of K + content began to rise. When the SSRWC was reduced to moderate and extreme drought (47% ~ 18%) from the 60th to the 80th day, all four types of wild apricot accumulated Na + as osmotic adjusting substances. For organic osmolytes, the soluble protein accumulated in the wild apricot under moderate to moderate drought stress, and the accumulation of soluble protein may be related to its drought resistance. When the stress is further aggravated, soluble sugar is the osmotic regulator . Eventually, the content of Pro increased sharply under extreme drought stress. The content of Pro in low LRWC was high, and its content was microgram level, far lower than other osmotic adjusting substances. Therefore, Pro does not participate in the osmotic adjustment of wild apricot under drought stress. The dramatic increase of Pro content is the result of the rate of protein synthesis in plants lower than its degradation rate and cell damage.