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Characterization and evaluation of the rice (Oryza saliva L.) cultivar
Njavara was undertaken in the Department of Plant Breeding and Genetics and
Biochemistry Laboratory, College of Horticulture, Vellanikkara during 1997-1999
with an aim to characterize Njavara genotypes based on morphological and
biochemical studies and to evaluate its nutritional qualities.
Morphological characterization indicated that the thirteen Njavara
genotypes were distinct among themselves and the Njavara genotypes NI (Njavara
type from Mulloorkara, Thrissur), N2 (Njavara type from Chittoor, Palakkad), N5
(Njavara type from Edavanna, Malappuram), NIl (Njavara type from Pattambi,
Palakkad) and NI3 (Njavara type from Thootha, Palakkad) yielded on par with the
check variety Ptb-IO, eventhough they were having extra short growth duration
compared to Ptb-I 0.
Biochemical characterization revealed the possibility of utilizing
peroxidase, esterase and protein polymorphism for identifying the Njavara
genotypes especially NI (Njavara type from Mulloorkara, Thrissur) , N2 (Njavara
type from Chittoor, Palakkad), N3 (Njavara type from Chittoor, Palakkad) and N4
(Njavara type from Chittoor, Palakkad) and also for the identification of Njavara as
a cultivar. Selecting some other isozymes coupled with enzyme activity studies and
opting for molecular markers were the other strategies suggested for characterization
of Njavara genotypes.
Majority of the Njavara genotypes expressed high protein content than
Ptb-l O. The genotypes N2 (Njavara type from Chittoor, Palakkad) and N8 (Njavara
type from Alwaye) were recommended to be included in weaning and invalid foods
due to high protein content. The genotypes N2 (Njavara type from Chittoor,
Palakkad), N3 (Njavara type from Chittoor, Palakkad) and NI2 (Njavara type from
Thrissur) appeared to have higher number and content of free amino acids. Most of
the Njavara genotypes had intermediate amylose and as such may not have any
problem with respect to consumer preference. Starch grain characterization revealed
that starch grain size could be used for varietal characterization in conjunction with
morphological and biochemical markers. Absence of flavonoids in Nj avara grain
indicated its nonaromatic nature. The genotype N7 (Njavara type from
Tellicherry, Kannur) was found to have better digestibility due to low amylose
content, high amylase activity and high soluble carbohydrate content.
Variability studies indicated that fat content, straw yield and grain yield
provided a good genetic base for selection. Correlation and path studies revealed
that grain yield could be improved by simultaneous selection for high straw yield
and longer leaves while selection for wider leaves, longer ligules, increased number
of days to 50 per cent heading, longer panicles and long duration genotypes favour
high free amino acid content. Low amylase activity, short and narrow leaves, shorter
panicles, low 1000 grain weight, slender grains, short duration genotypes and
smaller starch grains were observed to favour high protein content and selection for
tall culms, high 1000 grain weight and bold grains was found to favour high amylase
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