Rapid screening for drought tolerance in traditional landraces of rice (Oryza sativa L.) at seedling stage under hydroponics

Abstract

In the present investigation, a total of 50 indigenous rice genotypes collected from rice growing regions of Tamil Nadu were screened for their drought tolerance ability. The experimental setup comprises of hydroponic treatments with different levels of osmotic potential, upto (-) 15 bars in a progressive manner. Phenotypic responses showed that,30% of the landraces tested were highly susceptible and only 12% were highly tolerant to moisture stress on 26 DAS. The germination percent (GP) was significantly varied between 0.83 to 1.14 for stress (S) and control treatments respectively. The genotypes viz., kuliyadichan and rajalakshmi recorded high germination percent (1.18) compared to other land races under moisture stress condition. The significant mean root length varied from 10.65cm to 4.05cm and 13.65cm to 5.60cm at an OP of (-) 15 bars and control respectively. Similarly, the significant mean shoot length varied from 24.15 cm to 7.35cm under moisture stress ((-) 15 bars) and 38.25cm to 17.15cm under control. The highest R/S ratio was observed in kuliyadichan (0.87) while the lowest ratio was recorded by the genotype annada (0.18) at OP of (-) 15 bars. In addition, high SHR ratio (120.26) was also recorded for kuliyadichan and low SHR (8.99) for virendra. These results suggest that the genotypes kuliyadichan, chandaikar, mallikar, mattaikar, rajalakshmi and nootripattu represent better source-sink relationship. It is concluded that these genotypes can be used as donor candidates towards genetic improvement of drought tolerance (DT) in rice.

Keywords

• Rice landraces
• drought tolerance
• hydroponics
• PEG 6000
• source-sink relationship