Name: Shree Bhagavan Thakur Id. No.:
R-2009-PLB-B-05 P
Semester & the year of admission: First 2009 Degree: Doctor of Philosophy (Ph.D.)
Major subject: Plant Breeding Department: Plant
Breeding
Major advisor: Surya Kant Ghimire, Ph.D.
The experiment was conducted in a Randomized Complete Block Design (RCBD)
with 3 replications at National Oilseed Research Program (NORP), Nawalpur, Sarlahi "Genetic
variability on component traits of pod yield, drought tolerance and leaf spot
disease resistance of groundnut (Arachis hypogaea. L.)" during rainy season 2010
and 2011. Twenty five groundnut
genotypes were collected from National Oilseed Research Program (NORP),
Nawalpur, Sarlahi Nepal including local checks (B -4, Jayanti and Baidehi) and used
for the study. Observations were
collected from randomly selected five plants from each plot and averaged. Data were
computed and analyzed using SPSS software.
Highly
significant variations were observed for all the characters in all the
genotypes. Higher phenotypic coefficients of variations were observed for days
to 75% flowering, days to maturity, plant height, pods plant-1, seed
pod -1, 100 kernel weight,
pod length, pod width, seed length, seed width, selling % and sound matured
kernel %. Slightly higher phenotypic co-efficient of
variation was observed for all the traits compare to genotypic co-efficient of
variation indicating lesser effect of environment on the traits. The character
100 kernel weight showed high heritability with high genetic advance and high
genetic advance in percentage of mean. Considerable high heritability, low
genetic advance and genetic advances in percentage of mean were found for days
to maturity.
The genotype ICGV-99171, ICGV-98089,
ICGV-97100, Baidehi, ICGV-00440, and B-4 performed better under drought
condition with high pod yield. Hence, it is suggested that these genotypes
could be grown under regions of limited rainfall. These lines may be used as
parents in breeding program for developing drought tolerant groundnut
cultivars.
The results indicated that
genotype ICGV-91074, ICGV-88473, ICGV-92173, B-4, Rajashri, ICGV-91104 and
ICGV-98089 had lower level of Cercospora leaf
spot disease incidence. Genotypes ICGV-91074, ICGV-98089, ICGV-92173 and
ICGV-88473 produced higher pod yield and also had lower Cercospora leaf spot incidence. Genotypes ICGV-91104, ICGV-92173,
B-4 and ICGV-91074 produced higher haulm yield and had the lower Cercospora leaf spot incidence. This
study indicated that development or selection of tolerant/ resistant genotypes against
leaf spot disease should be based on their level of disease incidence.
Therefore, potential source of genetic resistance to this disease exist for
selection among genotypes used in this study. Pod yield showed highly
significant positive association with days to maturity, haulm yield and pod
length. Significant positive correlation with oil percent was observed with SLA
and SMK percent. Therefore, pod length and haulm yield are important traits for
pod yield and SLA and SMK percent are important for oil percent. These traits
should be considered while selecting for yield and oil content.
ICGV-98089, ICGV-92173,
ICGV-88473, ICGV-91074, ICGV-00350, ICGV-97100 and ICGV-99171 were found higher
pod yield, oil % and protein % compared to traditional genotype B-4 and
Jayanti.
Days to maturity, root
length, pod length and pod width showed direct and positive contribution to pod
yield. The correlation co-efficient of the pod yield ha-1 with days
to maturity, SMK%, pod length, pod width and kernel length was highly
significant and positive. The highly significant and negative association of the
pod yield ha-1 with days to flowering, pod plant-1,
shoots length, shelling percent and specific leaf area showed. Days to
maturity, root length, pod width, pod length and kernel length made the
individual high positive direct contribution to pod yield ha-1 while
partitioning component of the total yield. Days to flowering, shoot length,
shelling percent, SMK percent and100 kernel weights showed direct negative
contribution with pod yield ha-1. Therefore, days to maturity, root
length, pod width, pod length and kernel length were identified to be the
important traits which could be used in selection for yield.
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Surya Kant Ghimire, Ph.D.
Chairperson Advisory Committee
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Shree Bhagavan Thakur
Author
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