MSc

The present study was undertaken in the Department of Plant Breeding and
Genetics and in the Centre for Plant Biotechnology and Molecular Biology, College of
Horticulture, Ve!!anikkara and at RARS, Ambalavayal during 2008-2010 with an aim to
characterize the aromatic rice cultivars of Wayanad district, based on morphological,
nutritional and biochemical studies.
Gandhakasala and Jeerakasala are two popular and traditional non-Basmati
aromatic ricecultivars of Wayanaddistrict, Kerala. In Wayanad Gandhakasala is
cultivated in an area of 327 ha, while Jeerakasala in 22 ha. Based on grain characters 10
samples of Gandhakasala and two samples of Jeerakasala were selected for
characterization. Deepthi (WND.3) was used as check variety.
Among morphological studies, qualitative characters like leaf bladepubescence,
. panicle exsertion, spikelet awning, awn colour, lemma and palea pubescence and seed
. .
coat colour showed variation and hence these can be used as morphological markers to
distinguish aromatic genotypes among themselves and with Deepthi. Straw coloured
short and partial awns were the characteristic feature' of Jeer aka sa I a grains, while awns
were absent i!1 Gandhakasala and Deepthi. Aromatic genotypes exhibited well exserted
panicles and white seed coat colour whereas Deepthi showed moderately welIexserted
. .
panicles and red seed coat colour.
Mean performance of aromatic genotypes indicated that ligule length, grain
length, grain breadth, 1000 grain weight, days to 50 per cent heading, milling recovery
and maturity days provided a good base for selection. Jeerakasala genotypes took more
days to 50 per cent heading and to maturity than Gandhakasala genotypes and Deepthi .
. In general Gandhakasala genotypes had lesser 1000 grain weight with a mean value of
13.78 gm compared to Jeerakasala (19;82 gm) and Deepthi (26.17 gm). High grain
breadth and grain length would have added to high 1000 grain weight in Deepthi. In

general aromatic genotypes have lesser milling recovery than Deepthi, indicating the
need [or specially designed milling machines for maximum milling recovery.
The genotype GT2 appeared to have higher total carbohydrate content of 81.87
per cent/while it Was Iow for JT12 (58. 40%). Jeerakasala genotypes exhibited low mean
carbohydrate content of 61.06 per cent' compared to Gandhakasala( 69.56%) and Deepthi
(71.73%). The three Gandhakasala genotypes GT3, GT9 and GT7 exhibited intermediate
proteincontent, indicating their nutritional superiority.
The amylose content of aromatic genotypes ranged between 17.87(GT4) and
23.07 (GT2) percent. Five aromatic genotypes GT1, GT2, GT8, GTlO and JT12 had
intermediate amylose content. Since intermediate amylose rice is preferred in most of the
rice growing regions of the world, these genotypes will have better preference in market.
Most of aromatic genotypes under study were moderately aromatic, indicating their
suitability for commercial cultivation.
Biochemical characterization based on isozyme studies revealed the possibility of
utilizing peroxidase polymorphism for identifying the aromatic rice genotypes especially
Gandhakasala genotypes from other cultivars. Studies on esterase. polymorphism
revealed the presence of EST-2 band only in Deepthi indicating its use as a biochemical
marker to distinguish aromatic rice genotypes from Deepthi.
Heritability and genetic gain studies indicated that selection of characters like
length of sterile glumes, lOOO grain weight, grain length and peroxidase activity may be
effective in crop improvement programme.
Correlation and path studies revealed that grain yield could be improved by
simultaneous selection for high seedling height, grain breadth, milling recovery and straw
yield.