IDENTIFICATION OF SUITABLE BIOMARKERS AND SEED INVIGORATION TECHNIQUES FOR EARLY SEEDLING VIGOUR IN RICE (Oryza sativa L.)
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Date
2024-04-18
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PROFFESSOR JAYASHANKAR TELANGANA STATE AGRICULTURAL UNIVERSITY
Abstract
The investigation entitled “Identification of suitable biomarkers and seed
invigoration techniques for early seedling vigour in rice” was carried out to identify the
suitable biomarkers associated with early seedling vigour by evaluating twenty rice
genotypes and suitable seed invigoration techniques to enhance seedling vigour in rice.
The twenty varieties of rice released by PJTSAU were grown during Kharif 2022
at ARI Seed Production Farm, Seed Research and Technology Centre, Department of
Seed Science and Technology, Rajendranagar. The experiment was carried out in Dry
Direct Seeded Rice (DDSR) system in a plot of size 6.25 m2 using Randomized Block
Design for evaluating growth, yield and yield attributes. The seed morphological,
physiological and biochemical parameters of these rice genotypes were evaluated with
two replications using Completely Randomized Design. The data of field, seed, seedling
and biochemical parameters were subjected to cluster analysis and one variety from each
cluster was selected and subjected to ten priming treatments and evaluated for
physiological and biochemical parameters.
All the yield and yield attributing parameters for twenty genotypes were recorded
and seed samples were assessed for vigour and biochemical parameters. Analysis of
variance for yield, seed and seedling characters stated significant difference among the
varieties for all the parameters except for days to 50 % flowering and phosphate content.
The genotypes viz., JGL 24423, KNM 118, KNM 733, WGL 915 and WGL 1246 showed
superior performance under DDSR system and also reported superior seedling vigour
traits.
The correlation studies between seed vigour traits and seed, seedling, biochemical
and yield attributes reported that speed of germination and SVI II recorded a significant
positive association with seed dry weight, hull dry weight, seed length, seed width,
seedling vigour index - I, seedling length, seedling dry weight, plant height, panicle length
and 1000 seed weight and a negative association with root shoot ratio, while seedling
vigour index I had a significant positive correlation with seed dry weight, hull dry weight,
seed length, α-amylase activity, seedling length, seedling dry weight, panicle length, 1000
seed weight and seed yield per ha. Seedling vigour index –II also showed association with
spikelet fertility and α-amylase activity.
The genotypes were grouped into four clusters based on cluster analysis and one
popular variety from each cluster viz., JGL 24423, KNM 118, RNR 10754, WGL 915
were selected and subjected to seed priming treatments viz., Hydropriming, Gibberlic acid
(GA3) @ 40, 60 and 80 ppm, Salicylic acid (SA) @ 1, 2 and 3 Mm and KNO3 @ 2.5, 5
and 10 % at ambient conditions.
Analysis of variance of seed invigoration studies showed a significant difference
among the varieties, treatments and interactions for all the parameters under study except
for root shoot ratio which showed significant difference among the varieties, seedling
length, seedling vigour index I and α-amylase activity showed significant difference
among the varieties and treatments only. Among the various seed invigoration treatments
seed priming with SA @ 3 mM recorded highest germination, speed of germination,
seedling length, seedling vigour index I & II, α-amylase activity and phosphate content,
while GA3 @ 80 ppm recorded highest coleoptile and mesocotyl length, hydropriming
reported lowest root shoot ratio and KNO3 @ 10% recorded highest seedling dry weight.
Based on results it can be concluded that seed dry weight, hull dry weight, seed
length, seed width and α-amylase activity have direct positive influence and root shoot
ratio has negative influence on seedling vigour characters hence can be utilized as
biomarkers for early seedling vigour in rice. Among the various seed invigoration
treatments, seed priming with SA @ 3 mM is identified as best seed invigoration
treatments for early seed vigour enhancement in rice. High vigour genotype WGL 915
showed better response to invigoration, while genotype RNR 10754 showed low response
to invigoration.