A Study On The Relationship Between Cucumber Gynogenesis And Content Of Ovary Hormones And Polyamines

To investigate the relationship between cucumber gynogenesis and contents of hormones and polyamines in unfertilized ovaries, 5 genotypes with higher gynogenesis response and 4 genotypes with lower gynogenesis response were used as plant materials. Content of IAA, ZR, GA(3) and ABA in explants of unfertilized ovaries just before culture and at 3, 6, 9 and 16 days of culture were checked respectively. Free and conjugated polyamines including spermidine (Spd), spermine (Spm), putrecine (Put) and cadecine (Cad) of the above materials were also analyzied. The results showed that no direct relationship between IAA, ZR, GA(3) and ABA content in unfertilized ovaries before culture and cucumber gynogenesis response was found, but lower IAA/ZR, IAA/GA(3) and ABA/GA(3) was beneficial to in vitro gynogenesis response. Ratio of IAA/ABA decreased dramatically in genotypes with higher gynogenesis response after 3 days of culture. Genotypes with higher gynogenesis response have higher free and conjugated Spd+Spm content, higher total polyamines content, and lower ratio of Put/total polyamines than those with lower gynogenesis response. Spd was the major type of polyamine in the unfertilized ovary just before culture. Spd and Spm content decreased dramatically after 6 days of culture, whereas Put and Cad increased dramatically, and Put became the major type of polyamine at 6 d of culture.