Studies On Senescence And Ripeness Charactery Of Cucumber Fruit

In this experiment,cucumber breed D0313(premature senility) and 649(comparison) were used as materials to research cucumber fruit senescence.The experiment contend included three facets: first was fruit growth and development course ,second was physio-biochemical change,third was cucumber fruit peel cell ultrastructure .It can be the theoretical basis to find the mechanism of fuit senescence and breeding resisting senescence varieties.The results were as follows:1 In cucumber fruit growth pattern,cross section of D0313 increased more quickly,fruit growth stoped earlier; cross section of 649 increased more slowly went with vertical diameter, fruit growth stoped latter.The time of fruit peel colour of D0313 and 649 tured into yellow were 25d and 35d after pollination separately.About 30d after pollination,the seed began to mature,but,the seed of D0313 was no fuller than 649 the corresponding period.2 Went with cucumber ripeness and senescence course,the chlorophyll content decreased.On the whole,the chlorophyll content of D0313 was lower than 649, and the chlorophyll of D0313 decreased earlier and more quickly.3 In cucumber ripeness and senescence course,one member which cleaned out active oxygen ,POD showed two peaks; another member SOD increased in the early time,and then decreased when the cucumber fruit peel turned into yollow. In the changing time and speed,D0313 were earlier and more quickly than 649. Went on with cucumber fruit ripeness and senescence course,cell membrane degradation and product of peroxidation of membrane lipid MDA increased slowly.On the whole, the content of MDA of D0313 was higher than 649,that showed the peroxidation of membrane lipid of D0313was stronger,therefore,D0313 growed senile more quickly.4 The soluble protein content of D0313 decreased earlier than 649,and the speed was more rapid.The soluble protein content of D0313 was lower, that showed premature senility could reduced fruit nutrition quality.5 Cucumber was not respiratory climacteric rypes fruit,here was no respiratory peak in the ripeness.There was one peak of respiratary rate in the late time of cucumber senescence,this reflected the senescence of cucumber fruit.