辣椒果实成熟过程中硬度及相关生理生化指标的变化

The Changes of Characters Related to Fruit Firmness of Two Pepper(Capsicum annuum L.) Lines During Fruit Ripening

选用2个不同硬度的辣椒品系,在果实成熟的不同时期测定其果肉硬度变化,并测定了与硬度相关的原果胶、果胶和纤维素的含量以及促进细胞壁物质分解的PME,PG,纤维素酶和β_半乳糖苷酶等水解酶的活性。结果表明:果实硬度在转色期最大,随着果实成熟,可溶性果胶含量增加,纤维素含量从转色期开始基本呈下降趋势,从幼果期到转色期PME酶的活性呈上升趋势,529品系酶活性在转色期达到最大,585品系在绿熟期酶活性达到最大值。2个品系的PG酶活性不断上升并在红熟期达到最大值。纤维素酶的活性也呈上升趋势并在转色期达到最大值。2个品系的半乳糖苷酶活性在红熟期达到最大值。辣椒果实成熟软化过程中,其硬度的变化与果胶、纤维素等物质的变化有显著相关性,而这些物质的变化又与促进这些物质水解的细胞壁水解酶活性的变化相一致。在果实成熟的不同时期,这些硬度的相关生理生化指标可以反映出果实的硬度特点,在耐贮运辣椒育种过程中有一定参考价值。

Two pepper （ Capsicum annuum L. ） lines with different fruit firmness were selected and their fruit firmness was measured during the fruit ripening. Meanwhile, the characters related to the fruit firmness such as contents of primary pectin, soluble pectin, and cellulose were monitored, and the cell wall hydrolases such as Pectin Methyl-esterase （PME）, Polygalacturonase（PG）,β-Galactosidase, and Cellulase were also analyzed during ripening. The results showed that the maximal fruit firmness of both lines was at stage Ⅲ （co,or turning）, then the fruit firmness decreased during ripening, concomitant with the increase of soluble pectin content. The cellulose content of Line 529 decreased after stage Ⅰ （premature fruit stage）, but Line 585 changed a little. The PME activity of Line 529 was developed from stage Ⅰ and was maximal at stage Ⅲ, but the maximal PME activity of Line 585 was at green mature stage. The activity of PG increased continuously and was maximal at stage Ⅳ （red mature）. The activity of cellulase was increasing during fruit ripening and maximal at stage Ⅲ. The β-Galactosidasethe activity of two pepper lines reached the maximal value at the stage Ⅳ. These results suggest that the changes of fruit firmness was closely correlated with the contents of soluble pectin and the cellulose, which was further related to the PG, PME, β-Galactosidase and Cellulase activities during fruit ripen- ing. These related characters can reflect the firmness type of pepper fruit and provide information for the pepper breeding of storage and transportation tolerance.