CHARACTERIZATION AND GENOME WIDE ASSOCIATION STUDIES FOR INSECT RESISTANCE AND YIELD IN POTATO
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Date
2023-10-12
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UHF,NAUNI
Abstract
ABSTRACT
The present investigation was planned to assess theABSTRACT
The present investigation was planned to assess the genetic variability, correlation among tuber yield
and its component traits, their direct and indirect effects on tuber yield, clustering pattern of genotypes, and
genome-wide association studies for Tuta absoluta resistance and yield components in potato. The experimental
material comprising of 357 potato genotypes including varieties, advanced breeding lines and exotic germplasm
was evaluated in augmented block design for two consecutive years during the winter seasons of 2021-22 and
2022-23 at Nagrota Bagwan, Kangra, Himachal Pradesh. Data were recorded on average tuber yield per plant
and 22 morphological and biochemical traits in addition to 5 entomological traits. Sufficient genetic variability
was observed for yield and its related traits. Based on adjusted mean values, it was revealed that Kufri Garima,
CP 3585, CP 1767, CP 2390 and CP 1989 were the superior/desirable performing genotype mainly due to the
significant contribution of the number of tubers per plant and average tuber weight. High PCV and GCV were
observed for the number of stems per hill, plant height, number of compound leaves per plant, number of tubers
per plant, average tuber weight, average tuber yield per plant, total polyphenols and total carotenoids content
irrespective of years. High heritability coupled with high genetic advance was observed for majority of traits
during both the years indicating the importance of additive gene action for the inheritance of these traits.
Correlation and path analysis revealed that the number of tubers per plant and average tuber weight in addition
to tuber dry matter content could be advantageous for developing high-yielding genotypes. The cluster analysis
revealed maximum inter-cluster distance between CP 3081 and JEX/A 683, JEX/A 19 and CP 3091, JEX/A
1081 and CP 4594 during 2021-22, 2022-23 and pooled over the years, respectively. GWAS analysis indicated
significant marker-trait associations for different traits viz., tuber dry matter content, number of compound
leaves per plant, plant height, non-reducing sugars, tuber width, leaf damage and total plant damage. Further it
was observed that one SNP for plant height (chr04_3551782), two SNPs number of compound leaves per plant
(chr05_17842252 and chr08_14450306 for) while for Tuta absoluta resistance one SNP each i.e.
chr05_10199243 for leaf damage and chr09_53321787 for total plant damage were common in different
environments. The physical region in the candidate region of significant SNPs was inspected for putative
candidate genes for each test trait. For morphological and biochemical traits, candidate genes were identified on
six chromosomes i.e. chr04 (PGSC0003DMG400029501), chr05 (PGSC0003DMG401016322), chr06
(PGSC0003DMG400043458), chr08 (PGSC0003DMG400009402), chr09 (PGSC0003DMG400037214,
PGSC0003DMG400040489) and chr12 (PGSC0003DMG402002888, PGSC0003DMG400042800) which
encodes for specific functional groups or proteins. Besides, for Tuta absoluta resistance traits, candidate gene
‘PGSC0003DMG400018458’ were identified on chr05 involved in electron carrier and gene
‘PGSC0003DMG402001013’ present on chr09, encodes for DNA polymerase eta.y, correlation among tuber yield
and its component traits, their direct and indirect effects on tuber yield, clustering pattern of genotypes, and
genome-wide association studies for Tuta absoluta resistance and yield components in potato. The experimental
material comprising of 357 potato genotypes including varieties, advanced breeding lines and exotic germplasm
was evaluated in augmented block design for two consecutive years during the winter seasons of 2021-22 and
2022-23 at Nagrota Bagwan, Kangra, Himachal Pradesh. Data were recorded on average tuber yield per plant
and 22 morphological and biochemical traits in addition to 5 entomological traits. Sufficient genetic variability
was observed for yield and its related traits. Based on adjusted mean values, it was revealed that Kufri Garima,
CP 3585, CP 1767, CP 2390 and CP 1989 were the superior/desirable performing genotype mainly due to the
significant contribution of the number of tubers per plant and average tuber weight. High PCV and GCV were
observed for the number of stems per hill, plant height, number of compound leaves per plant, number of tubers
per plant, average tuber weight, average tuber yield per plant, total polyphenols and total carotenoids content
irrespective of years. High heritability coupled with high genetic advance was observed for majority of traits
during both the years indicating the importance of additive gene action for the inheritance of these traits.
Correlation and path analysis revealed that the number of tubers per plant and average tuber weight in addition
to tuber dry matter content could be advantageous for developing high-yielding genotypes. The cluster analysis
revealed maximum inter-cluster distance between CP 3081 and JEX/A 683, JEX/A 19 and CP 3091, JEX/A
1081 and CP 4594 during 2021-22, 2022-23 and pooled over the years, respectively. GWAS analysis indicated
significant marker-trait associations for different traits viz., tuber dry matter content, number of compound
leaves per plant, plant height, non-reducing sugars, tuber width, leaf damage and total plant damage. Further it
was observed that one SNP for plant height (chr04_3551782), two SNPs number of compound leaves per plant
(chr05_17842252 and chr08_14450306 for) while for Tuta absoluta resistance one SNP each i.e.
chr05_10199243 for leaf damage and chr09_53321787 for total plant damage were common in different
environments. The physical region in the candidate region of significant SNPs was inspected for putative
candidate genes for each test trait. For morphological and biochemical traits, candidate genes were identified on
six chromosomes i.e. chr04 (PGSC0003DMG400029501), chr05 (PGSC0003DMG401016322), chr06
(PGSC0003DMG400043458), chr08 (PGSC0003DMG400009402), chr09 (PGSC0003DMG400037214,
PGSC0003DMG400040489) and chr12 (PGSC0003DMG402002888, PGSC0003DMG400042800) which
encodes for specific functional groups or proteins. Besides, for Tuta absoluta resistance traits, candidate gene
‘PGSC0003DMG400018458’ were identified on chr05 involved in electron carrier and gene
‘PGSC0003DMG402001013’ present on chr09, encodes for DNA polymerase eta.