Abstract This study aimed to characterize papaya lines via microsatellite markers, and select genotypes based on the fixation index in order to promote the genetic purification of important commercial hybrids parent lines. Overall, 400 genotypes from three parental lines (JS-12, SS-72/12, and Sekati) were genotyped. Expected (HE), observed (HO) heterozygosity, and fixation index (F), were estimated. Genetic distances were estimated using an unweighted index, which was graphically presented via cluster analysis using the UPGMA and PCoA. Intra-genotypic variability was detected in both JS-12 and Sekati lines, while an absence of it was observed in SS-72/12. Such variability may positively contribute to the fitting of ‘UENF/Caliman 01’ and ‘UC-10’ hybrids into the traits of commercial interest how size and weight fruit. Regarding the fixation index, 293 genotypes showed maximum values (F=1) facilitating the genotypes selection process. Concerning population analysis, a close proximity between heterotic group ‘Formosa’ lines was observed, while a greater distance among ‘Solo’ group ones, and this enables systematic exploitation of such material. The fixation index maximum enabled the 80 genotypes selection thereby contributing to the parents genetic purification, since, the selected genotypes will be used in future hybridization steps to generate hybrids fitted into the traits of commercial interest.

ABSTRACT Selection indexes represent the real efforts of a breeding program to obtain genetic gains for various significant traits simultaneously. As such, this study selected superior F5 lines by combined selection for fruit quality using an index based on predicted genotypic values via residual or restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) methodology weighted by agronomic weights. To do so, 97 F5 papaya lines obtained by the single seed descent method, resulting from the biparental cross between the genotypes JS-12 and Sekati, were evaluated for the main traits related to fruit quality. Results of the analysis of deviance and the genetic parameters indicated that there was genetic variability, indicating possible success in the selection process. Based on the selection index, 29 lines were selected as superior for fruit quality with ‘Formosa’ pattern. The strategy of the selection index combining BLUPs of multiple traits of interest associated with agronomic weights allows maximizing genetic progress while discarding less-promising genotypes.

Abstract: Part of the success of a breeding program depends on the composition of the base population. Superior genotypes and unimproved dioecious varieties are sources of genes for traits of interest and excellent options for the formation of segregating populations. Here we describe the first cycle of recurrent selection (RS) in papaya and propose an effective strategy, unprecedented in the crop, to generate variability and new cultivars. Initially, the RS base population (UCP-C0) was developed with wide variability. Subsequently, 196 S1 progenies were obtained, evaluated in a trial, and the superior 40 S1 progenies were recombined. Among the traits of the selected progenies, high fruit yield (producing two to five fruits per axil) stands out. The S1 progenies were recombined and their seed bulk corresponds to the base population for the second cycle (UCP-C1). The results of the first cycle demonstrate the genetic potential of this population for the development of superior cultivars, and the breeding strategy applied is promising.

ABSTRACT: The growing demand for quality of papaya by the domestic and international markets requires the development of genotypes that are capable of incorporating traits, such as high yield and fruit quality. This study estimated the genetic parameters and the specific combining ability of F4 papaya lines crossed to the SS-72/12 tester to identify genotypes with higher genetic value for hybrid production. We evaluated 169 treatments consisting of 62 topcross hybrid combinations, 97 F5 lines, and 10 controls in a 13 × 13 lattice design with five replicates and two plants per plot. The following traits were evaluated: plant height (PH), stem diameter (SD), first-fruit insertion height (FFIH), number of marketable fruits (NMF), number of deformed fruits (NDF), number of fruitless nodes (NFN), average fruit weight (FW), and yield (YLD). Differences p < 0.05 were found in most traits evaluated. The specific combining ability estimates indicate that hybrids formed by the cross between SS-72/12 tester and the following lines are promising, considering the multiple traits: UCLA08-088, UCLA08-101, UCLA08-071, UCLA08-014, UCLA08-025, UCLA08-028, UCLA08-122, UCLA08-055, UCLA08-026, and UCLA08-092. These hybrids meet the demands for domestic and international markets and may be available to producers as new papaya cultivars.

ABSTRACT Developing superior lines based on a simultaneous response from many traits of agronomic importance is a fundamental strategy to expand papaya cultivar supply, mainly the much-needed cultivars belonging to group Formosa. Our goal was to associate the pedigree method with REML/Blup procedure to select plants of progenies F2:3 with superior agronomic performance. The variance components and genetic parameters were estimated using REML approach, and the genetic values were predicted using Blup methodology. The combined selection was performed using the IG2 selection index based on weights associated with agronomic values to indicate the best progenies and lines. The heritability estimates of progeny mean were high in most traits and evidenced significant genetic variability between progenies. The narrow-sense individual heritability was moderate in traits such as commercial fruits and soluble solid contents, which indicates a favorable condition for selections within progenies. The index was consistent in the selection of six superior progenies according to the assessed traits. This index also enabled promising genetic gains in traits of great interest such as yield and pulp thickness. Although the progenies are derived from self generations, they proved to be superior in traits of significant importance such as yield, commercial fruits, and pulp thickness when compared to the Tainung-01 hybrid, which is a worldwide-planted cultivar used as a reference to Formosa representatives. Six lines were selected within the superior progenies to continue the Formosa group-lines development program. The association of the pedigree method with REML/Blup procedure can be useful to assist breeders in an autogamous breeding program.

Abstract The papaya cultivar UC14, recommended for the Southeast and Northeast regions of Brazil, was developed by UENF/CALIMAN breeding program. ‘UC14’ produces smaller fruit than those of Formosa hybrid, with a mean weight of 0.8 kg and a mean fruit yield of 199.45 t ha-1.

Abstract UC10 is a new papaya cultivar, recommended to the southeast and northern regions of Brazil. It has a very good agronomic performance in and adaptation to these regions, with Formosa fruits of approximately 1.9 kg and yield of 260 t ha-1. The cultivar has early fruit production, and fruits have excellent flavor.

Abstract Over the last three years, Brazil has been ranked among the three largest producers of papaya. This study aimed to evaluate the acceptance and commercial standard of papaya fruits according to their sensory traits and provide information about the organoleptic and qualitative aspects of the fruit. Ten papaya genotypes grown in Linhares-ES were investigated, arranged in a randomized block design with four replications. Ten fruits from each genotype were randomly collected from each replication, which totaled 40 fruits per genotype. The fruit harvest was performed at stage 1 of maturation. The following genotypes were assessed: hybrids UC13, UC14, UC15 and UC16, from the ‘Solo’ group; hybrids UC03, UC10 and UC12, from the ‘Formosa’ group; and ‘Golden’, ‘Calimosa’ and ‘Tainung 01’, which were used as controls. The sensory evaluation of the genotypes was carried out in full balanced design by 50 evaluators. When submitted to sensory analysis, the hybrids showed high performance compared to the controls of each group. Traits such as aroma, flavor and overall impression were crucial in the selection carried out by the appraisers of the hybrids assessed. The hybrids UC10, UC12, UC14 and UC16 were the most accepted and preferred, respectively, in purchase intention.

Abstract UENF Rioparaíba common bean cultivar from the black commercial group has a high grain yield (2351 kg ha-1), stability, and wide adaptation to the Northern and Northwestern regions of the state of Rio de Janeiro. The new cultivar contains 20.7% crude protein and has a mass of 1000 seeds equals to 256.8 g.

Abstract The present work aimed to estimate the adaptability and stability of new papaya hybrids. The experiments were carried out at the company Caliman Agrícola S/A, in the municipalities of Linhares-ES and Pureza-RN, with seven hybrids from inbred parents of the groups ‘Solo’ and ‘Formosa’ and three controls (‘Golden’, ‘Calimosa’, and ‘Tainung 01’). The experiment consisted of a randomized block design with four replications and ten plants per plot. The variables mean fruit weight (MFW), number of commercial fruits (NCF), and production (PROD) were measured at 270, 360, 450, and 540 days after planting. Afterward, the adaptability and stability of the hybrids were estimated using the Lin and Binns, Eberhart and Russell, and Mixed Models. MFW was less affected by the evaluation periods and showed high behavior predictability. The hybrids UC10, UC12, UC14, UC15, and UC16 were the most adapted and predictable and can be recommended for the regions where the experiment took place.

ABSTRACT: The selection of superior Carica papaya (L) genotypes depends on the availability of genetic variability and on the favorable and simultaneous response of the genotypes to those traits of most interest. However, manual phenotyping (MP) demands intensive labor, is time-consuming and expensive. The aim of the current study is to access the efficiency of image-based phenotyping (IBP) in estimating genetic parameters and in selecting F4 recombinant inbred lines. The genetic parameters and values were estimated in accordance with the REML/BLUB procedure and combined selection using the selection index based on standardized genetic values. The majority of traits accessed through IBP showed experimental coefficients of variation similar to those found through MP. Both methodologies showed genetic parameters of similar magnitude, indicating expressive genetic variability between lines in the traits accessed in this study. The same superior lines were indicated in both methodologies and expressive genetic gains obtained through the lines were selected for all traits. IBP performance was similar to that of MP with respect to the estimates of breeding-relevant traits such as commercial fruits and yield. Thus, IBP showed efficient phenotypic assessment, as well as selective accuracy in accessing genetic variability and genetic gains, when it was compared to MP. Since IBP is far less dependent on labor, it is expected to be incorporated into the routine of papaya breeding programs as a way of increasing the number of accessed lines and, consequently, increasing genetic gains.

Abstract UENF 2014 is a new common bean cultivar from the black commercial group, developed by UENF. The cultivar is adapted to the Northern and Northwestern regions of the Rio de Janeiro state and presents a good performance, mainly for high grain yield, high stability and wide adaptation to these regions.