Effectiveness of selection, parent-offspring correlation and regression in bacterial blight resistance genes introgressed rice segregating population

Abstract

The effectiveness of early generation selection was practiced in bacterial blight resistance genes introgressed F2 and F2:3 population of the cross CB 174 R × IRBB 60 in rice. F2 Selection have been proved to be robust and effective tool in crop improvement program. Selection differential was positive for all studied traits. Selection response was high for number of grains, thus indicating the effectiveness of selection for these character. Realized heritability was found high for number of grains and thousand grain weight, suggested that direct selection was effective. Expected selection response and predicted genetic gain was high for number of grains. Parent-offspring correlation showed low but significance association for number of productive tillers (r=0.47**, P<0.01), single plant yield (r=0.35**, P<0.01) and (r=0.30*, P<0.05) panicle length in F2 and F2:3 generation indicates that selection was fruitful in early generation. Statistically regression coefficient was not significant linear dependence of the mean of F2 and F2:3 generation.

Variability and genetic diversity study in an advanced segregating population of rice with bacterial blight resistance genes introgressed

“…These results are in agreement with Ponnaiah, Manonmani and Robin (2016) for panicle length and Govintharaj et al (2016) for thousand grain weight. In F 2:3 families, the variability parameters recorded were very low because stringent selection was imposed in the F 2 generation and selection was effective (Govintharaj et al, 2017). The current study showed that a wide range of variability was exhibited for the traits under this study.…”

Parent progeny regression analysis in segregating generations of drought QTLs pyramided rice lines (Oryza sativa L.)

“…Hence, selection for high yield in the earlier generations is necessary for achieving the target of yield improvement under drought tolerance. A high mean with a large amount of variation in the segregating generations is needed for the development of elite cultivars (Govintharaj et al, 2017). Hence, to know the association and heritability of the traits contributing to yield in the drought QTLs introgressed segregating population of rice, parent progeny regression analysis was carried out.…”

Introgression Progress for Phenotypic Traits and Parent-progeny Diversity at Advanced Segregation Population From Oryza Barthii and Oryza Glaberrima/oryza Sativa Crosses

“…Selection response of traits differ among traits and the most effective generation to make selection for each trait based on correlation and regression analyses outcome equally differs. In respect of segregation generations, many authors (Vanniarajan and Ramalingam, 2011; Govintharaj et al, 2017;Aananthi, 2018) have hinted that selection at earlier generations are most effective for many traits. Majority (88%) of our measured traits may be conforming to the above since our single plant selection program commenced at F 6 .…”

“…The obtained paired similarity distance was employed and subjected to principal component and clustering analysis. The parent progeny correlation and regression analysis between F6 with F7 and F7 with F8 was carried out following the procedure of Govintharaj et al (2017) and Aananthi (2018). To further identify the introgressive trend for each genotype for the combined 15 phenotypic traits, similarity of each genotype to the two parents was performed for F 6 , F 7 and F 8 data using Gower genetic distance in SAS (version 9.4 (SAS, 2011).…”