Characterization of interspecific hybrid progenies of guava using morphological, biochemical and molecular traits

Guava is one of the important commercial fruit crops of India, but its production suffers from wilt and nematode complex infection. Thus, screening of wild species resulted in the identification of Psidium cattleianum as one of the sources of resistance. Involving resistant source, interspecific hybrids were developed using ‘Arka Poorna’ and ‘H 12-5’ (Psidium guajava) as the female parents with P. cattleianum var. cattleianum and P. cattleianum var. lucidum as the male parents. In the present study, previously identified 42 resistant interspecific hybrids were characterized based on morphological, molecular and biochemical (phenolic acid and volatile profiling) traits in comparison with their parents at vegetative stage. Among 15 morphological traits, leaf traits viz., leaf blade shape was obovate in eight progenies and leaf base shape was obtuse in 27 progenies resembling male parent. As regards leaf tip, acute shape was found in 35 progenies resembling to P. cattleianum (male parent) and this trait could act as a morphological marker for the identification of hybrid progenies at vegetative stage. The molecular markers (simple sequence repeats, SSR), mpgCIR220 and mpgCIR253 were highly reproducible and could effectively confirmed the hybridity of interspecific hybrid progenies of P. cattleianum var. lucidum and P. cattleianum var. cattleianum, respectively. In addition to morphological and molecular markers, the levels of few volatile compounds viz., β-borbonene, aristolene, (E, Z)-alpha-Farnesene, trans-gamma-bisabolene, neryl acetate, linalyl acetate and furan, 2-ethyl, were similar to those of their male parents. These novel volatiles, morphological traits and molecular markers can be used to enhance the speed of breeding by reducing time for progeny identification.