【目的】揭示钙对脐橙裂果的作用机理.【方法】以抗裂果的‘纽荷尔’ Citrus sinensis cv.Newhall 和易裂果的‘朋娜’Citrus sinensis cv.Skagg’s Bonanza为试材,进行外源补钙和钙吸收抑制剂处理,在不同时期记录果实裂果率,测定果皮钙含量和纤维素酶( CX)、多聚半乳糖醛酸酶( PG)、果胶甲酯酶( PE)的酶活性.【结果和结论】抗裂的‘纽荷尔’的果皮钙含量高于易裂的‘朋娜’,同一品种正常果的果皮钙含量高于裂果;花后150 d,质量分数为2%Ca(OH)2的处理可以显著提高果皮钙含量,提高果皮硬度,降低裂果率;质量分数为2%Ca(OH)2处理与CX酶活性呈负相关关系;钙能通过影响细胞壁酶活性影响裂果,其中对‘朋娜’影响显著,对‘纽荷尔’作用不明显.
Objective] The objective of the study was to find the relationships among calcium contents , cell wall enzyme activities and fruit cracking .[Method] Two naval orange ( Citrus sinensis) cultivars,‘Skagg ’ s Bonanza ’ and ‘Newhall ’ were treated with exogenous calcium or calcium uptake inhibitor . The contents of calcium , the rate of fruit cracking and the activities of polygalacturonase ( PG) , cellulase ( CX) , and pectinmethylesterase ( PE) were investigated in different periods .[Result and conclusion]The contents of calcium in ‘Newhall’ was higher than that in ‘Skagg’s Bonanza’.The content of calci-um in the normal fruits was higher than that in cracked fruits in the same cultivar .The mass fraction 2%Ca( OH) 2 treatment increased significantly the calcium content in the pericarp and fruit firmness , reduc-ing the rate of fruit cracking 150 days after anthesis.The mass fraction 2%Ca(OH)2 treatment reduced the activities of cellulase ( CX) .Calcium affected the incidence of fruit cracking through its effect on the activities of cell wall enzymes .Its effect was significant in ‘Skagg ’ s Bonanza ’ but not in ‘Newhall ’ .