枣易裂与抗裂品种灌水后果皮结构和扩张蛋白基因表达差异研究

Differences in the Pericarp Structure and the Expression of Expansin Genes After Irrigation Between Easily Cracked and Resistant Jujube

以枣易裂果品种‘李府贡枣’和抗裂果品种‘皖枣3号’脆熟期果实为试材,分析了灌水后枣果果肩、赤道和果顶各部位硬度、果皮显微结构和细胞扩张蛋白基因表达的差异。结果显示:灌水30 h后‘李府贡枣’果肩裂开,‘皖枣3号’果实各部位硬度都大于‘李府贡枣’,‘李府贡枣’赤道和果顶硬度大于果肩;‘皖枣3号’果实表皮细胞排列紧密度和规律性优于‘李府贡枣’,‘李府贡枣’赤道和果顶表皮细胞排列紧密度和规律性优于果肩,赤道和果顶部位果皮厚度大于果肩,但灌水后增幅小于果肩;‘皖枣3号’果肩果皮中扩张蛋白EXPA类基因ZjEXPA4、ZjEXPA5-like、ZjEXPA6、ZjEXPA14和ZjEXPA17表达量都显著高于‘李府贡枣’。

To understand the cracking-resistant mechanism of Ziziphus jujuba,the crisp mature fruits of the cracking-resistant‘Wanzao 3’and cracking-susceptible‘Lifu Gongzao’were used as materials to measure fruit firmness and pericarp microstructure in the shoulder,equator and top,and to detect the expression levels of expansin genes in shoulder pericarp of the two cultivars under irrigation using real time PCR,respectively. The results showed that the shoulder of ‘Lifu Gongzao’was cracked after irrigation 30 h. The fruit firmness of the shoulder,equator,and top of‘Wanzao 3’was significantly higher than that of‘Lifu Gongzao’respectively,and the firmness of the equator and top of‘Lifu Gongzao’was significantly higher than that of the shoulder under irrigation. Pericarp cells of‘Wanzao 3’were arranged more tightly and regularly than those of‘Lifu Gongzao’,and pericarp cells of the equator and top of‘Lifu Gongzao’were arranged more tightly and regularly than the shoulder under irrigation. Pericarp thickness of the equator and top of‘Lifu Gongzao’was more than that in the shoulder,however,the increased thickness of the equator and top was less than that of the shoulder under irrigation. The expression levels of EXPA genes Zj EXPA4,Zj EXPA5-like,Zj EXPA6,Zj EXPA14,and Zj EXPA17 in the shoulder pericarp of‘Wanzao 3’were higher than those of‘Lifu Gongzao’under irrigation.