Quantification of floral abnormalities in a population generated from sexual polymorphism aiming at recurrent selection in papaya

Abstract

The aim of this study was to estimate the percentage of deformed fruits (carpelloid, pentandric, and bananoid), summer sterility, repeatability coefficients, and correlations among the variables for floral abnormalities; and select genotypes with the lowest incidence of deformed fruits and summer sterility. In the experiment, which involved 254 plants, traits were evaluated using the digital-phenotypic method and the obtained images were processed and analysed using ImageJ v1.48 software with the Cell Counter plugin. Summer sterility had the highest percentage of occurrence in the evaluated periods. Based on the quantification of total abnormalities, the 30 genotypes with the lowest incidence of floral abnormalities were selected. Summer sterility is the main BASIC AREAS -Article problem of the papaya crop in terms of floral abnormalities. The non-significant correlations between the traits: NDF/TNF+NFN (number of deformed fruits/number of fruits + number of fruitless nodes) and NFS/TNF+NFN (number of fruitless nodes/number of fruits + number of fruitless nodes); NDF/TNF+NFN and NFN/SUM (number of fruitless nodes/sum of abnormalities); and NFS/TNF+NFN and NDF/SUM (number of deformed fruits/sum of abnormalities) indicate that the variables are independent of each other. Of the 254 evaluated progenies, at least 30 were identified as having potential for selection, with lower occurrence of total floral abnormalities.

Recurrent selection in papaya: An effective strategy for the continuous development of new cultivars

“…Luz et al (2015) found lower means of 24.30, 14.98 and 0.66 for these same traits, respectively, when evaluated papaya hybrids. Moreira et al (2019), in specific studies for summer sterility and for carpeloidy and pentandry rates, verified that the repeatability coefficients varied from low to intermediate due to the quantitative nature of the evaluated traits, which are highly influenced by environmental factors. For these traits, each cycle of recurrent selection seeks to reduce deformities and sterility and increase the quantity of commercial fruits in the population.…”

Combining ability of recombined F4 papaya lines: a strategy to select hybrid combination

“…High CVe values indicate low experimental precision. The low experimental precision found for NMF, NDF, and YLD may be associated with summer sterility, since sterility (NFN) increases in hotter months of the year, whereas the rates of carpellody and pentandry (NDF) increase in colder months (Moreira et al, 2019). This opposition between sterility and pentandry and/or carpellody in these months alters the data on the number of fruits, which results in high data dispersal and high experimental error.…”

Methylation related genes affect sex differentiation in dioecious and gynodioecious papaya

“…Hermaphrodite flowers abort carpels and reverse to functional male flowers [ 11 ]. These floral abnormalities caused by adverse environmental conditions have a negative effect on fruit production, leading to reduced yield [ 12 , 13 ]. Uncovering the underlying mechanism of sex determination and maintenance process would result methods to improve papaya with no sex reversal to increase fruit production.…”