The use of seedling root and shoot traits to predict the saleable yield of elite red papaya genotypes

ABSTRACT Determining the saleable fruit yield of red hermaphrodite papaya (C arica papaya L.) relies on waiting until tree maturity. Recombinant inbred lines (RIL) seedlings (F6‐F7 RIL) were assessed for fresh root length, fresh shoot weight, fresh shoot width, dry root weight and dry shoot weight during three growth stages after sowing (0‐30 days after sowing; DAS, 31–60 DAS and 61–90 DAS). During the 31–60 DAS period, significant intra‐genotypic variation was observed for each trait across the RIL assessed. A strong genotypic correlation at growth stage II was predicted among the traits ( P < 0.05 ; r g > 0.60), with a moderate to high broad‐sense heritability (H 2 b.s ; > 0.30) and with genetic advances of up to 10% in the RIL compared to the parental genotypes. Growth stage II was most reliable for predicting saleable fruit yield ( R 2 = 0.73) with levels of influence of traits measured across the RIL in the following order: fresh root length (40% to 70%) > dry root weight (20% to 50%) > dry shoot weight (10% to 48%) > fresh shoot width (13% to 38%) > fresh shoot weight (1% to 42%). Hence, these F7 genotypes will be used to develop new F1 hybrids with significant increases in saleable fruit yield.