15 RESEARCH REPORTS PNL Volume 11 1979
Kaul, M. L. H. and R. Garg University of Kurukshetra, India
After X-irradiation of 'Bonneville1, many high protein mutants were
isolated in the M3 generation (1). But these were very tall, late, and low
yielding and with small, shrivelled, and deformed seeds. These mutants were
intercrossed among themselves, back-crossed to the parental line, and crossed
with other high yielding mutants. Recombinants with high grain yield, better
seed protein content, and less shoot height were selected in F3 and selfed
for 4 generations. Their performance was evaluated by growing them in a
randomized block design with 4 replications per genotype. The protein values
recorded are the lowest values obtained for the genotypes 1-14. But for the
local line the values recorded are the average of 30 plants per season grown
for 4 successive generations. Genotype No. 2 has been included because of
its earliness. The average performance of the selected lines (Table 1) indi-
cates that the lines 14, 13, 3, 5, and 6 are promising (in order of their
superiority) and are better than the commonly cultivated local line in this
region. Moreover, except for line 13, these lines are not tall, and their
breeding value is thus very high.
The analysis of variance (F value, Table 2) reveals a highly significant
variance in each phenotypic trait among the genotypes. Nevertheless, internode
length appears to be of environmental origin. A high genotypic variance for
the shoot height and seed number points to the possibility of a successful
selection of short statured, high yielding plants among these genotypes.
Furthermore, the genotypic coefficient of variation, indicating the extent
of observed variation due to genetic factors, was high for seed yield and
seeds per plant (Table 2). Nevertheless, the heritability values were very
high for shoot height, nodes and seeds per plant, and seed yield. However,
while heritability estimates are subject to genotype environment interaction,
genetic advance expressed as the percentage of mean was highest for the traits
seeds per plant and total seed yield and lowest for shoot height and nodes ]
per plant.
Thus, the traits seed yield and seeds per plant showed a high genetic
coefficient of variation, heritability, and expected genetic advance, and
they are highly and positively intercorrelated (Y=2.59 + 0.16X, r=0.73,
P< 0.01). These results are encouraging from the standpoint of practical
breeding and selection.
(1) Kaul, M. L. H. 1977. Proc. 3rd Sabroa Congress (Australia). 3c:36-41.