成熟期不同品种枣果肉微观组织结构特征

Fruits microstructure characteristics of different jujube varieties during maturity

【目的】从细胞组织结构角度揭示不同品种、不同成熟期枣果肉组织结构的差异性及变化规律,定量解析枣果肉微观结构特征,为不同品种枣的品质对比及枣果适时采收提供参考。【方法】选取骏枣、灰枣和马牙枣3个品种,在白熟前期(Ⅰ)、白熟期(Ⅱ)、脆熟半红期(Ⅲ)、脆熟全红期(Ⅳ)和完熟期(Ⅴ)5个时期分别取样,采用石蜡切片和显微成像技术获取枣果肉细胞结构参数并进行相关分析。【结果】3个品种枣果肉组织的形态学参数间存在差异。灰枣果肉组织细胞的面积、周长、横径、纵径和等效直径明显小于骏枣和马牙枣,骏枣和马牙枣相当。各品种的圆形率由大到小依次为灰枣、马牙枣、骏枣。骏枣组织内孔隙分布较其他2个品种多。3个品种枣果肉组织细胞的面积、周长、横径、纵径、等效直径和圆形率均为先增大,在Ⅱ期后减小,在Ⅲ期后趋于平稳,而间隙率变化趋势相反,为先减小,在Ⅱ期后增大,在Ⅲ期达到最大后趋于平稳。不同品种枣果肉组织细胞圆形率变化特征有较大差异:灰枣果肉组织细胞的圆形率无显著变化,骏枣和马牙枣均出现较大波动。枣果肉微观组织细胞结构参数变化主要集中在Ⅰ-Ⅲ期,且不同品种各参数变化率绝对值不同。随着枣果成熟,灰枣果肉组织内细胞参数值均增大;骏枣果肉组织细胞的面积、周长、横径、圆形率和间隙率均增大,其纵径和等效直径减小;马牙枣果肉组织细胞的圆形率和间隙率整体增大,其面积、周长、横径、纵径和等效直径均减小。【结论】不同品种枣果肉微观组织结构特征及其成熟期变化存在一定差异。枣果肉细胞的圆形率越大、间隙率越小,果肉结构越致密、质地越硬。枣果肉细胞的面积、周长、横径、纵径、等效直径和圆形率的变化趋势一致,而间隙率的变化趋势与之相反。宜在脆熟半红期之后采收枣果。

【Objective】The differences and changes of the pulp structures of different jujube varieties in different maturity stages according to cell structures were revealed,the microstructural characteristics of jujube fruit was quantitatively analyzed,aiming to provide basis for quality comparison among different jujube varieties and the timely harvesting.【Method】Ziziphus jujuba cv.Jun zao,Ziziphus jujuba cv.Hui zao,and Ziziphus jujuba cv.Maya zao were used as materials,which in the early white maturity stage(Ⅰ),white maturity stage(Ⅱ),crispy and semi-red stage(Ⅲ),crispy full red stage(Ⅳ)and mature stage(Ⅴ)were sampled separately.Paraffin sections and microscopic imaging techniques were used to determine the structural parameters of jujube pulp cells for related analysis.【Result】There were differences among three dates varieties on flesh tissue morphological parameters:cell area,circumference,transverse diameter,longitudinal diameter and equivalent diameter of Ziziphus jujuba cv.Hui zao were significantly smaller than that of Ziziphus jujuba cv.Jun zao and Ziziphus jujuba cv.Maya zao,which two dates were equivalent.The roundness order was Ziziphus jujuba cv.Hui zao>Ziziphus jujuba cv.Maya zao>Ziziphus jujuba cv.Jun zao.The cell area,perimeter,transverse diameter,longitudinal diameter,equivalent diameter and circular rate of three jujube varieties increased firstly,decreased after stage Ⅱ,and stabilized after stage Ⅲ.The voids rate changed in the opposite direction,which firstly decreased to stage Ⅱ and then increased to stage Ⅲ,and the fruits variation characteristics of different jujube varieties were quite different:the circular rate of Ziziphus jujuba cv.Hui zao had no significant change;both Ziziphus jujuba cv.Jun zao and Ziziphus jujuba cv.Maya zao showed large fluctuations.The changes of cell structure parameters of jujube pulp were mainly concentrated in stage Ⅰ to Ⅲ.The area,circumstance,transverse diameter,longitudinal diameter and equivalent diameter of Ziziphus jujuba cv.Jun zao were more than those of the other two cultivars.During the maturity,the cell parameter values of Ziziphus jujuba cv.Hui zao pulp tissue increased overall.The cell area,perimeter,transverse diameter,circular rate and gap rate of Ziziphus jujuba cv.Jun zao increased overall,while the longitudinal diameter and equivalent diameter decreased as a whole.The cell circular rate and the viods ratio of Ziziphus jujuba cv.Maya zao increased,and the area,circumference,transverse diameter,longitudinal diameter,equivalent diameter all decreased as a whole.【Conclusion】There were some differences in the pulp microstructures characteristics among three cultivars.The bigger roundness,the smaller voids;the more compacter of the pulp structure,the harder of the texture.The cell area,circumstance,transverse diameter,longitudinal diameter,equivalent diameter and roundness of jujube pulp had the same trend of variation,and the opposite variable trend of the clearance rate.Jujube fruit harvest should be carried out after the crispy and semi-red period.