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采用WinRhizo2005a根系扫描测定系统和石蜡切片法,研究亚低温(8～15℃)和轻度干旱(正常田间持水量的55%～70%)胁迫对番茄幼苗根系形态及叶片结构的影响.结果表明:亚低温和轻度干旱单一胁迫促进了番茄幼苗根系长度、表面积和体积的增加,而二者交互胁迫导致番茄根系各指标下降;亚低温和轻度干旱单一胁迫下番茄幼苗通过增加0.50～1.00mm径级比例来促进根系长度的增加,通过增加1.00～2.00mm径级比例来增加根系表面积和体积,交互胁迫下番茄幼苗通过减少0.20～0.50mm和<0.20mm2个径级的比例来延缓根系生长.叶片组织结构疏松度(SR)与组织结构紧密度(CTR)呈显著负相关,CTR与栅海比呈显著正相关;亚低温处理下栅栏组织厚度减小,轻度干旱胁迫下栅栏组织和海绵组织厚度均减小,交互胁迫使叶片变薄,栅海比显著降低.
The effects of mild hypothermia (8-15 ℃) and mild drought (55% -70% of normal field water) stress on the root morphology and leaf structure of tomato seedlings were studied by using root scanning system and paraffin section method of WinRhizo2005a.The results showed that : Single hypoxia and mild drought stress promoted the root length, surface area and volume of tomato seedlings. The interaction of the two factors led to the decrease of each index of tomato root. Under the single stress of mild hypothermia and mild drought, tomato seedlings increased 0.50-1.00 mm diameter scale to increase the root length. The root surface area and volume were increased by increasing the diameter of 1.00 ~ 2.00mm. The root system was delayed by decreasing the proportion of 0.20 ~ 0.50mm and <0.20mm2 diameter classes under the mutual stress (SR) and tissue structure density (CTR) were negatively correlated with each other.The CTR was positively correlated with the ratio of grid to sea, and the thickness of the palisade tissue was decreased under mild hypothermia, but the palisade tissue under mild drought stress And sponge tissue thickness were reduced, the interaction stress thinning leaves, grid-sea ratio decreased significantly.