Evaluation on calyx characters of Pyrus pyrifolia fruit

Pear fruit with calyx persistent,commonly known as‘Gongli',didn't look so good that it wasn't popular with people.Before the factors affecting calyx abscission and persistence were studied,the calyx characters of different pear germplasm had to be mastered.In order to know about the calyx characters of different Pyrus pyrifolia cultivars,the investigation was performed in Pyrus pyrifolia Germplasm Nursery of Fruit-Tea Institute,Hubei Academy of Agricultural Sciences.The calyx state,calyx posture,calyx concave width,calyx concave depth and calyx concave state of 316 cultivars were investigated.After sepals off stage,100 fruits' calyx characters of each cultivar were observed and assigned.SPSS 16.0 was used to analyze statistically.The results showed that 316 cultivars were divided into 10 groups by calyx abscission rate,with 10% as a unit.The distribution diagram of frequency showed with a shape of‘U'.Both of the number in the first(calyx abscission rate10%) and the tenth group(calyx abscission rate≥90%) were obviously higher than other 8 groups,numbers of which were small and relatively similar.In contrast,when they were divided into 7 groups by calyx abscission rate,with 5% and 20% as units,the performance frequency standard deviation showed inversion‘U',suggesting that the calyx abscission rate of varieties with very low rate(calyx abscission rate5%) or very high rate(calyx abscission rate≥95%) was most stable.Calyx posture,calyx concave width,calyx concave depth and calyx concave state of cultivars had two main phenotypes,the proportions of which were more than 30%,and their Simpson diversity index was between 0.585 and 0.722,meaning that their performance were relatively similar.Conclusion: this study could be guidance of cultivars selection,for studies on mechanism of calyx abscission and persistence,and breeding new germplasm.