Studies On Chilling-resistance Indices Appraisal And Selecting On Bitter Gourd Varieties

Bitter gourd is distributed to tropics and subtropics area. As it grows in tropic climates, hypothermia will lead to dysontogenesis. Many of the studies today lay store on its function, very few of them on breeding, and there's still no reported work on chilling-resistance breeding. So this experiment aimed to study on appraisal indices of chilling resistance and chilling-resistance-index screening on this special vegetable. This work would help to enhance the efficiency of identifying and screening breeding materials for shelter cultivation.This experiment used six bitter gourd varieties as material to study on nine different biochemical and physiological indices of chilling resistance and their correlations and also made observation on six agronomy and horticultural traits, explored its relationship with chilling-resistance ability. The main results were as follows:1. As for chilling index of controlled low temperature conditions, significant difference were observed among six bitter gourd varieties, so chilling index was a useful index to appraise the chilling-resistance ability of bitter gourd varieties.2. Electric conductivity percentage of bitter gourd leaves cultivated at 30℃ temperature treated at 8℃ low temperature for 16 hour was a useful index to appraise the chilling-resistance ability of bitter gourd varieties.3. As for the content of Pro determined on 15℃-low-temperature-cultivated bitter gourd, significant difference were observed among six bitter gourd varieties, and significant negative difference were also observed between the content of Pro and chilling-resistance factor. So content of Pro was a useful index to appraise the chilling-resistance ability of bitter gourd varieties.4. As for the content of MDA determined on 15℃-low-temperature-cultivated bitter gourd, significant difference were observed among six bitter gourd varieties, and significant negative difference were also observed between the content of MDA and chilling-resistance factor. So it can be used as a method to appraise the chilling-resistance ability of bitter gourd varieties.5. With the help of factor analysis, ten indices were reduced as three factor named as chilling-resistance factor, photosynthesis factor and germination factor. Factor cluster analysis showed that six varieties belongs to three clusters.6.Factor analysis showed that six maturity associated horticultural traits were reduced as two factor named as blooming factor and bearing factor. Factor cluster analysis showed that six varieties belongs to two clusters.