温岭高橙三倍体杂种抗冻性研究

A Comparative Study on the Freezing Resistance between Triploid Hybrid Breeding and Female Parent Wenling Gaocheng Orange

摘要: 以15年生投产的三倍体浙农无核橙柚与母本二倍体温岭高橙为试材，在冻害调查的基础上，相继利用气孔、电导率、LT50、SOD、CAT、MDA、ABA、PRO对叶片的冻害结果进行检测鉴定。气孔体征研究显示，温岭高橙受冻后的气孔密度增加7.80%、面积减少3.65%，同比，浙农无核橙柚气孔密度增加7.20%、面积减少5.73%。冻害前后母本气孔密度显著大于杂交后代，面积则与之相反。冻害发生后三倍体杂种气孔长轴长于母本，短轴短于母本，逆境时闭合能力强。冻害发生前后，母本电导率分别是杂交后代的1.40倍、1.13倍，形成极显著差异。MDA含量浙农无核橙柚低于温岭高橙。杂交后代的蛋白浓度、SOD含量分别大于母本32.31%、44.87%。浙农无核橙柚ABA浓度和PRO浓度分别高于母本32.66%和7.06%。半致死温度的测定结果表明，浙农无核橙柚低于温岭高橙。综合研究认为，浙农无核橙柚作为三倍体杂种其抗冻性显著强于母本二倍体温岭高橙。三倍体的杂种优势在抗冻性上优势明显，体现了高值亲本的特点。

Abstract: In this study, 15 years Zhenong seedless orange triploid hybrid breeding and 30 years diploid female parent Wenling Orange are used as test materials, to detect and identify the freezing injury of the leaves based on freezing injury investigation by using stoma, conductivity, SOD, CAT, MDA, ABA, PRO. Stomatal signs showed that the stoma density of Wenling Gaocheng increased by 7.80% and the stoma area decreased by 3.65% after freezing injury, while the stoma density of triploid hybrid Zhenong seedless orange-pomelo increased by 7.20% and the stoma area decreased by 5.73% at the same condition. The stomatal density of female parent was significantly higher than that of the hybrid progeny before and after freezing injury, but the stomatal area was just the opposite. After the freezing injury, the stomatal macroaxis of the triploid hybrid progeny is longer than that of female parent, while the minor axis is shorter than that of female parent, and the stomatal closure ability is stronger in adversity. After that, the electrical conductivity, functional enzyme activity and hormone content were detected and analyzed. Before and after the freezing injury, the female parent’s electrical conductivity was 1.40 times and 1.13 times higher than that of the hybrid progeny, which formed a very significant difference. MDA content of Zhenong seedless orange triploid hybrid was lower than Wenling Orange. The protein concentration and SOD content of the hybrid progeny was greater than that of female parent by 32.31% and 44.87% respectively. ABA content and Pro content were 32.66% and 7.06% higher than Wenling Orange, respectively. Lethal temperature of Zhenong seedless orange-pomelo was lower than Wenling-gaocheng Tangelo. In conclusion, the comprehensive study showed that, as a triploid hybrid, the freezing resistance of Zhenong seedless orange-pomelo was significantly stronger than that of the diploid female parent Wenling-gaocheng Tangelo. Triploid hybrids have obvious advantages in freezing resistance, which reflects the characteristics of high-value parents.