自然低温下白菜型冬油菜内源激素和总多酚含量的变化

Changes of Endogenous Hormones and Total Polyphenols for Winter Turnip Rape (Brassica rapa L.) Subjected to Low Temperature

为揭示西北寒旱区白菜型冬油菜内源激素和总多酚含量与其抗寒特性的关系,以强抗寒冬油菜品种陇油7号和弱抗寒品种天油4号为试验材料,在田间自然低温条件下,分别取植株的叶片和根系,测定分析内源激素脱落酸(ABA)、生长素(IAA)、赤霉素(GA3)、玉米素核苷(ZR)和总多酚含量的变化。结果表明,冬前和越冬期,间随着气温的降低,2个白菜型冬油菜品种从苗期到越冬期,叶片和根中IAA含量和(IAA+ZR+GA3)/ABA值、叶片中ZR和ABA含量、根中GA3含量和IAA/ZR值均呈先升高后降低的趋势;而叶片中GA3含量和根中ZR含量在陇油7号中均呈下降趋势,在天油4号中均呈先升高后降低的趋势。随着气温持续降低,陇油7号根中ABA含量呈升高的趋势,在天油4号根中则呈先升高后降低的趋势;2个白菜型冬油菜品种叶片中以及陇油7号根中总多酚含量均呈先升高后降低再升高的趋势,天油4号根中总多酚含量呈先缓慢降低而后升高的趋势。相关性分析结果表明,越冬率与冬油菜叶片中IAA和ZR含量以(IAA+ZR+GA3)/ABA的值呈负相关,而与其根中ABA和总多酚含量呈正相关。与强抗寒品种冬油菜陇油7号相比,在降温中后期(11月17日后,-4.75℃),弱抗寒品种冬油菜天油4号叶片中IAA、ZR和ABA含量、(IAA+ZR+GA3)/ABA值和总多酚含量整体均较高,而其根中ABA和总多酚含量整体均较低,说明冬油菜越冬前地上部生长越旺盛,其抗寒性越差。综上所述,白菜型冬油菜根中内源激素ABA和总多酚含量对其抗寒性具有重要作用。本研究为白菜型冬油菜抗寒性受内源激素调控和总多酚影响提供了部分理论依据。

To reveal the relationship between content of endogenous hormones total polyphenols and cold-resistance, winter turnip rape Longyou 7(cold resistant) and Tianyou 4(cold sensitive) were used as experimental material. Under low temperature in the field, leaves and roots of plants were sampled to analyze the contents of endogenous hormones(IAA, ZR, GA3 and ABA) and total polyphenols, respectively. The results showed that IAA contents and ratio of(IAA+ZR+GA3)/ABA in leaves and roots of these two cultivars, ABA and ZR contents in leaves, GA3 contents and ratio of IAA/ZR in roots increased at first, and then decreased with decreasing temperature;GA3 contents in leaves and ZR contents in roots in Longyou 7 decreased, which increased at first, and then decreased in roots of Tianyou 4. As the temperature continued to drop, ABA contents increased in of roots Longyou 7, but increased at first, and then decreased in roots of Tianyou 4;total polyphenols contents in leaves of these two cultivars and roots of Longyou 7 increased at first, then decreased, and increased at last, decreased at first, and then increased in roots of Tianyou 4. The correlation analysis showed that overwintering rate of winter turnip rape had negative correlation with contents of IAA and ZR as well as ratio of(IAA+ZR+GA3)/ABA in leaves under lower temperature, but had positive correlation with contents of ABA and total polyphends in roots. Compared with Longyou 7, contents of IAA, ZR, ABA, total polyphenols and ratio of(IAA+ZR+GA3)/ABA in leaves of Tianyou 4 were higher after November 17th(-4.75℃), but contents of ABA and total polyphenols in the roots were lower. In conclusion, the faster growth in over ground parts, the worse cold resistance, and contents of ABA and total polyphenols in roots play important roles in cold tolerance. This study provided the theoretical reference for effect of endogenous hormone and polyphenols on cold tolerance of winter turnip rape.