Abstract
Resistant Starch (RS), plays a crucial role in human health and nutrition by controlling glucose metabolism. RS or dietary fibre content in rice is low because it goes through a variety of process before it is ready for cooking and consumption. Hence, this study was carried out to develop a rice mutant with increased RS. The rice mutant (γ278) with increased RS was developed by utilizing gamma (γ) rays as a mutagen. Mutant γ278 was characterized for mutations in the starch biosynthetic genes
viz
.,
GBSSI, SSI, SSIIa, SSIIIa, SBEIa
, and
SBEIIb
to reveal the functional mutations/variations led to high RS content in rice. A total of 31 sequence variants/mutations in six genes were identified. We report the discovery of three deleterious mutation/variants each in
GBSSI, SSIIa
, and
SSIIIa
with the potential to increase RS content in rice. Further,
wild
×
mutant
crosses were made to develop an F
2
population to study the effect of combination of deleterious mutations. The SNP (
GBSSI
:
ssIIa
:
ssIIIa
) combination responsible for high RS content in F
2
population was identified and recorded highest amylose content (AC) (26.18%) and RS (8.68%) content. In conclusion, this marker combination will be highly useful to develop a rice variety with increased RS.