Diallel Cross Application and Histomolecular Characterization: An Attempt to Develop Reference Stock of Labeo ariza.

Simple Summary: Diallel crosses are breeding schemes used to estimate combining ability and the effects of reciprocal crosses among strains or varieties. Using this diallel cross scheme, we produced a crossbred population of Ariza labeo (Labeo ariza), a newly potential aquaculture species in Bangladesh. The improved performances of this crossbreed were observed phenotypically (growth performances) and genetically (variation at selected microsatellite loci) and manifested through myofiber histology. Captive breeding of this species in carp hatcheries of Bangladesh could be initiated and facilitated through maintaining the gene pool of the L. ariza of Kangsha and the Atrai River. Conservation could also be considered for advancing the better performer crossbred (G4K♀A♂) as the reference diallel crossbred. The simple yet efficient breeding technique and the manifestation of growth performances using histological and phenotypical observations will encourage the hatchery operators of Bangladesh and elsewhere to initiate the induced breeding of L ariza in large scale aquaculture. The objective of the present study was to evaluate the growth performance and genetic variation in diallel crosses of Ariza labeo (Labeo ariza) originating from three geographically separated rivers (Atrai, Jamuna and Kangsha) in Bangladesh. Intra (G1K♀K♂, G2J♀J♂, and G3A♀A♂) and inter (G4K♀A♂, G5K♀J♂, G6A♀K♂, G7A♀J♂, G8J♀K♂, and G9J♀A♂) stocks were produced following diallel cross (sex ratio—1:1 and n = 48; 16 from each river). Reproductive and growth performance, muscle cellularity and genetic variation following genotyping of eight microsatellite markers (Lr1, Lr2, Lr3, Lr22, Lr24, Lr27, Lr28 and Lr29) and analysis of all crossbreeds was performed. The fertilization (95% ± 2.11%), hatching (88% ± 1.03%), and survival rates (82% ± 1.88%) of G4K♀A♂ were higher compared to other groups. With respect to length and weight gains (2.67 ± 0.4 cm and 3.39 ± 0.2 g), SGR (3.23% ± 0.20%), and heterosis (8.87% and 24.74%) G4K♀A♂ was the superior group. A higher number of hyperplastic muscle fibers, mean number of alleles (2.75) and mean observed heterozygosity (0.417) from G4K♀A♂ could be interpreted to mean that G4K♀A♂ comprise better performance efficiency compared to others and are considered for continuing the L. ariza stock improvement program. [ABSTRACT FROM AUTHOR]