5种山杏优良无性系花器官抗冻性比较

Comparison with Freezing Resistance of Flower Organs Five Prunus sibirica Fine Lones

以甜仁(16号)、自交亲和(22号)、丰产(28号)、抗冻(41号)和晚花(94号)5种山杏优良无性系花器官为研究对象,采用低温胁迫处理的方法研究其抗冻性。结果表明:山杏花器官的褐变率和相对电导率均随温度的降低而渐增,总体上呈S形曲线,生理指标和形态指标相吻合。利用Logistic方程对相对电导率随温度的变化曲线进行了拟合,求出LT50值,花瓣LT50为-3.903～-4.664℃、雄蕊为-3.166～-3.660℃、雌蕊为-2.916～-3.254℃。低温处理时间在温度接近LT50时对相对电导率有显著影响,而过高于或低于LT50时影响不明显,所以以LT50为主要指标对花器官的抗冻性进行判断,可知花瓣抗冻性>雄蕊抗冻性>雌蕊抗冻性。因为雌蕊对低温敏感脆弱且是结果实的器官,所以采用雌蕊的抗冻性评价山杏无性系花期的抗冻能力。基于相对电导率的山杏无性系花器官抗冻能力为41号>94号>28号>22号>16号,与基于花器官褐变率的各无性系花器官抗冻能力排序基本一致。

Abstract： The flower organs of 5 Prunus sibirica fine clones, including ＂Sweet almond＂（No.16）,＂self-compatibility＂ （No.22）, ＂high yield＂（No.28）,＂freezing resistance＂（No.41） and ＂late flowering＂（No.94）, were used as experimental material, and the research of freezing resistance adopted the method of low-temperature stress tests. The browning percentage and the relative electrical conductivity of flower organs of Prunus sibirica increased gradually as temperature decreased, which showed a S-shape curve, and the change of physiological index conformed to the morphological index. To obtain LTs0 values, Logistic equations between the relative electrical conductivity and temperature were fitted. LTs0 of petal was between -3.903°C and -4.664°C,LT50 of androecium was between -3.166°C and -3.660°C, LTso of gynoecium was between -2.916°C and -3.254°C. When the temperature was near lethal temperature, low temperature lasting time had significant influence on the relative electrical conductivity of flower organs. Otherwise, the time had no significant effect on the relative electrical conductivity of flower organs.So LT50 is the major index for judging the freezing resistance of the flower organs, petal〉 androecium〉 gynoecium. According to the freezing resistance of gynoecium and the relative electrical conductivity, the freezing resistance of Prunus sibirica fine clones florescence was as follows, No.41〉 No.94〉 No.28〉 No.22〉No.16, which were in general accord in the order of the freezing resistance of the fine basing on clones browning percentage.