Genotypic evaluation of rice (Oryza sativa) for tolerance to zinc stress under hydroponic culture

摘要

One of the most important adaptive responses for crop plants involves their ability to deal with soil mediated abiotic stresses involving either deficient or excessive levels of mineral and metal ions in the soil. Zinc deficiency is one of the most widespread limiting factors to crop production. Correction of Zn deficiency via fertilization is not always a successful strategy due to agronomic and economic factors. To cope up with zinc deficiency, the efficiency of certain of those genotypes which are able to grow and yield well under Zn deficient conditions can be exploited. As an attempt to scavenge the genetic potential of the genotypes towards tolerance to zinc stress, an experiment was conducted at Tamil Nadu Agricultural University, Coimbatore, India. Ten rice genotypes Norungan, Pokkali, ASD16, CO47, TRY 2, White Ponni, ADT 38, PMK 3, Pusa Basmathi and IR 72 were subjected to graded levels of zinc under hydroponic culture employing modified Hoagland solution as the nutrient medium. The performance indices in terms of visual symptoms and growth characters revealed their relative efficiency to zinc stress. Norangan, Pokkali and ASD 16 possessed better zinc efficiency as evident from their higher uptake of Zn and translocation to the shoot; CO 47, TRY 2, White Ponni and IR 72 are medium tolerant and PMK 3, ADT 38 and Pusa Basmathi are susceptible to zinc stress.