PRODUCTIVE TRAITS AND MOLECULAR GENETICS CHARAC-TERIZATION (RAPD AND ISSR) OF SELECTED LONG SHANK LENGTH AND CONTROL LINES IN THE 6th GENERATION OF JAPANESE QUAIL

Abstract

The main objectives of this investigation were to characterize the possible genetic and productive traits differences associated with the selected line of long shank length after six generations of selections in Japanese quail compared to the control line. Productive traits and DNA markers were used to identify these lines. Line significantly affected BW and SL at 14, 21, 28 and 35 days and age at first egg favoring the selected line. Females had higher insignificant (P > 0.05) BW and SL than males at all studied ages except for one day old of age. Selected line matured at earlier (P≤0.05) age and had shorter (P≤0.05) days needed to produce the first 10 eggs than the control line. The selected line laid higher first egg weight, EW10 and EM10 than the control line with insignificant differences between them. From the present results, it can be concluded that selected long shank length line had favored growth traits and studied egg production related traits. The level of polymorphism among two Japanese quail lines was estimated using two PCR-based DNA marker techniques RAPD and ISSR. Each line represented by three females and two males. Six RAPD and 6 ISSR primers were employed to find out genetic variations and relationships among these genotypes. RAPD and ISSR analysis generated a total number of 456 and 470 amplicons representing a level of polymorphism of 48.333% and 46.552%, and an average number of polymorphic fragments/primer of 4.833 and 4.5, respectively. The genetic relationships among the 10 individuals of quail were estimated in terms of similarity using Dice coefficients. The genetic similarity ranged from 0-1 for RAPD, ISSR, and RAPD and ISSR combination. The interline relationships among the two quail lines based on RAPD, ISSR, and RAPD and ISSR combination revealed the highest genetic similarity between female of the control line and female of the selected line, male control and male selected line, and male control and female selected line, respectively. The interline relationships among the two quail lines based on RAPD, ISSR and RAPD and ISSR combination revealed the lowest genetic similarity between male and female control line and male and male control line, female control and male selected line, and male and female control line, respectively. The RAPD based dendrogram clustered the selected long shank length females and male genotypes in the same group while, selected female, selected male and control females and males were in separate clusters. The ISSR based dendrogram clustered the control males in the same group while, control females and selected females and males were delimited in separate one cluster. The RAPD and ISSR combination based dendrogram clustered the selected females and males in the same group, and selected male and control females and males in separate clusters. However, the reshuffling in the position of the selected long shank length and control genotypes belonging to the individuals in the different dendrograms revealed that they share common genetic background. They might share some genes between selected and control lines through selection in selected line. Moreover, each of the RAPD and ISSR was successful in identifying genotype-specific markers characterizing 10 individuals of Japanese quail. The productive traits and molecular genetic analysis used in the present study successfully distinguished between the two lines, selected line of long shank length and control line, females and males to estimate the genetic variability between them in order to enhance selection and breeding programs.