高温逆境胁迫对油桃生理特征影响的研究

Physiological Characteristics of Nectarine Seedlings Under High Temperature Stress

为分析油桃的耐热特性,为耐热品种选育研究奠定基础,以‘早红珠’油桃嫁接苗为试材,研究不同高温胁迫下植株形态特征和生理指标的变化。试验发现,随着温度持续升高,受害指数加大,33、39℃高温胁迫对植株生长影响小,45℃高温胁迫3天后植株热害症状明显;高温胁迫下,植株生理指标呈规律性变化,随着温度升高,叶绿素(Chl)和类胡萝卜素(Car)含量降低,且随胁迫持续下降幅度越大;除胁迫初期外,丙二醛(MDA)含量呈微增—减少—增加趋势;脯氨酸(Pro)含量逐渐增加,但45℃高温条件下,随着胁迫延长其含量急剧下降;超氧化物歧化酶(SOD)活性持续缓慢升高,除45℃高温处理第3天外,其活性在其他处理时增幅小;过氧化氢酶(CAT)活性先升后降,39℃处理时达峰值;高温下植株受害指数与Chl、Car、MDA、Pro、SOD及CAT等生理指标间具有显著相关性。

In order to analyze high temperature resistance of nectarine and provide foundation for high temperature tolerant variety breeding, the grafted nectarine seedlings of‘Zaohongzhu＇were used as materialsto study the changing tendency of morphological characteristics and physiological indices under different hightemperature stresses. The results showed that the injury indices increased with the rising of the temperature,little influence was found under 33 and 39℃, the symptoms of high temperature stress were obvious under 45℃for 3 consecutive days. The physiological indices of plant changed regularly under high temperature stress, thecontents of Chl and Car decreased with the temperature rise, and the descending range increased with thesustaining of the stress. MDA content showed a slightly increase- decrease- increase trend except at the initialstress stage. Pro content increased gradually, but decreased sharply under 45℃. SOD activity kept a slowincrease, the activity increased with a small range except on the 3rdday under 45℃. CAT activity increased atfirst and then decreased, and reached a peak at 39℃. The plant injury indices were significantly correlatedwith Chl, Car, MDA, Pro, SOD and CAT under high temperature stress.