Pollen morphological analysis of papaya (Carica papaya L.)

Abstract

There is little information on pollen morphological analysis of papaya cultivars with different flesh color and origins. We observed pollen morphological characters of 17 papaya cultivars through scanning electron microscopy. The results showed that papaya pollen grains were monads, tricolporate, and small and medium-sized. The pollen grains were oblate-spheroidal to spheroidal. Foveolate, reticulate, and fossulate exine ornamentation were observed. Colpi width had maximum coefficient of variation of 25%; Shannon diversity index of all qualitative characters reached over 0.8. Using cluster analysis, 17 papaya cultivars were divided into three groups; there was no relationship between flesh colors and origins. The study findings suggest that pollen morphological analysis is valuable to provide references for breeding and genetic improvement of papaya.