Evaluation of seed physiological quality of papaya elite hybrids, their reciprocal crosses and parents

Célia Maria Peixoto De Macedo,Deisy Lúcia Cardoso,Messias Gonzaga Pereira,Roberto Ferreira Da Silva

doi:10.1590/s2317-15372013000200008

Abstract

This study aimed to evaluate the physiological quality of seeds of three hybrid combinations and their reciprocals, as well as the selfed parents, and to estimate genetic parameters associated with seed quality, and possible reciprocal effects. The experiment used F1 hybrid papaya seeds and their reciprocal crosses between JS12 and Sunrise Solo 72/12, Sekati and Waimanalo, and the seeds of the parents and two varieties, totaling 12 treatments in a completely randomized design with four replications. Weight of 1,000 seeds, germination, seedling fresh weight and seedling dry weight, first count, speed of germination and seedling emergence were determined. There was no xenia effect for weight of 1,000 seeds and seedling fresh weight. The reciprocal effect was not expressed for germination and seedling emergence, while for the other traits, it was not expressed only for JS12 x Sekati. Differences among hybrids and their parents occurred as a result of the action of pollen in the crosses, and justified by early heterosis. The most sensitive vigor tests to discriminate differences in performance of hybrids and their reciprocals were speed of germination and seedling fresh weight. There were high magnitudes of the estimates for the genotypic determination coefficient for most of the evaluated variables, except for seedling fresh weight.

Highlights

Brazil is the world’s largest producer of papaya, with an annual production of 1,792,594 t in 2009, a decrease of 5.2% compared to the 2008 harvest
The aim of this study was to evaluate the physiological quality of seeds of three elite hybrids, their reciprocals and the selfed parents, as well as estimate genetic parameters associated with seed quality and possible reciprocal effects among the papaya hybrids studied
The methodology used for drying seeds in this study was efficient to achieve levels of water content close to what is considered ideal for studying the quality of papaya seeds

Summary

Introduction

Brazil is the world’s largest producer of papaya, with an annual production of 1,792,594 t in 2009, a decrease of 5.2% compared to the 2008 harvest. The dependence on imported seeds can be reduced as a result of the release of hybrid UENF/Caliman 01 This was one of nine hybrids whose production was based on the study by Marin et al (2006), who used partial diallel crosses to determine combining abilities and identify promising hybrid combinations. According to Berbert et al (2008), papaya seeds behave more to orthodox seeds, whose viability is extended by simultaneously reducing water content and temperature during storage. This behavior has advantageous implications for preserving germplasms for extended periods of time

Objectives

Methods

Results

Conclusion