Author

Poonam Chetry and Shanti S. Sharma*

Abstract

Aluminium (Al) toxicity is a primary constraint to plant productivity on acidic soils posing a threat to global food security. Here, we have monitored the impact of Al on photosynthetic pigment (chlorophyll and carotenoids) contents of certain rice (Oryza sativa L.) landraces from Sikkim Himalaya with contrasting Al tolerance namely, Kalo tukmar (KT), Champasari (CP), Krishna bhog (KB) and Dhansey (DH). Seedlings were grown hydroponically with half strength Hoagland solution containing Al (0-1500 µM, pH 4.5) for 14-d and chlorophyll (a, b and total) and carotenoid contents were measured. In response to the exposure to Al, pigment levels declined in a concentration dependent manner in all the tested landraces with strong landrace-specific differences. Thus, the extent of Al-induced decline in chlorophyll and carotenoid contents was much lower in KT and CP than that in KB and DH. A decline of 42, 50, 69 and 70% in total chlorophyll content at 1500 µM Al was evident in KT, CP, KB and DH, respectively. The observations are consistent with greater Al tolerance of KT and CP as compared to KB and DH. Chl a : b ratio tended to increase due to Al with landrace and concentration specific quantitative differences; minimum effect was evident in CP. The ratio increased by 91 and 45% at 1500 µM Al in KB and KT, respectively. The increased ratios suggest a higher Al-induced decline in Chl b content than that in Chl a.  The carotenoid contents were suppressed by 55 and 38% in KB and KT, respectively due to 1500 µM Al treatment. Differential response of the tested landraces to Al could be ascribed to variations in cellular management of Al burden. The findings have implications for selection of suitable landrace(s) for acidic soil conditions. 

Pages:149-154

Doi Number 10.61289/jibs2024.12.05.396

Keywords Acidic soils, Al toxicity, Photosynthetic pigments, Rice landraces, Sikkim Himalaya