不同生理苗龄西瓜断根嫁接苗生长和生理特性的研究

Effects of Seedling Age on the Growth and Physiological Characteristics of Grafted Watermelon Seedlings

为确定西瓜断根嫁接苗最佳的出圃时期,本试验研究了不同苗龄下西瓜断根嫁接苗形态和生理参数的变化。结果表明,西瓜断根嫁接苗的最佳出圃时期为2叶1心至3叶1心期,对应的日历苗龄为嫁接后21~24d,此时嫁接苗生长受根域体积的限制较小,嫁接苗的质量较高。生理苗龄大于3叶1心则会导致接穗徒长,下部叶片衰老黄化,根系吸收矿质营养的能力下降,不利于定植后的生长。

To find out the optimal transplanting stage for root pruning hole insertion grafted watermelon seedlings, the growth and physiological changes of grafted seedlings under different physiological ages were investigated. The results showed that the optimum transplanting stage for the grafted watermelon seedlings is the second or the third true leave of watermelon seedlings is fully expanded, about 21-24 days after grafting, at this period the seedlings had less space limitation to the root size. As the seedling age was older than three true leaves, the seedlings would grow excessively, resulting in lower leaves yellowed, weakened mineral absorption capacity of root.