Genetic diversity of papaya (Carica papaya L.) F5 recombinant inbred lines using the Ward-MLM strategy

The development of segregating populations in papaya allows the development of new high fruit yield and excellent fruit quality pure line or hybrid cultivars. The aims of this work was to carry out a descriptive analysis and estimate the genetic divergence between 99 papaya genotypes, with 97 recombinant F5 inbred lines from the UC-10 hybrid and the respective parents. These genotypes were evaluated in a Topcross, with a 13 × 13 lattice statistical design, with five replicates and two plants per plot. The genetic divergence between the F5 lines was estimated by the Ward-MLM methodology, based on 16 morpho-agronomic and fruit quality traits. Differences p < 0.01 were found for all traits for the source of genotype (adjusted) variation. Heritability ranged from 0.48 to 0.95. The variation index was higher than the unit for the traits PH (1.11), NCF (1.02) and FW (1.98). The descriptive analysis showed that there is a genetic diversity for all evaluated traits in the 97 lines under study. The Ward-MLM methodology was efficient in discriminating the inbred lines with consistent formation of three groups. The genetic diversity observed in papaya lines will allow the selection and indication of lines to be used in crosses with other elite testers to obtain hybrids, which meet the needs of national and international markets regarding to size, quality and fruit yield. The genetic potential of these lines was already expected, mainly because they are segregating from the UC-10 hybrid, which is well accepted in the consumer market.