Screening of rice (Oryza sativa L.) genotypes for zinc efficiency under zinc stress condition

Abstract

Soil zinc deficiency limits the growth and crop yield. Zinc is important micronutrient for both crop growth and human nutrition. In rice production, yields are often reduced and Zn concentration in grains is often low when Zn is in short supply to the crop. This may result in malnutrition of people dependent on a rice based diet. Growing Zn efficient cultivars i.e. cultivars with high yield at low Zn supply would represent a long term solution for sustainable approach to crop production. To evaluate Zn efficiency of 20 diverse rice genotypes, field experiment was conducted during kharif seasons for two consecutive year using Zn deficient (0.42 mg kg-1) sandy loam soil, treated with 0 kg Zn ha-1 (no Zn low level), 5.0 kg Zn and 10.0 kg ha-1. The relative grain yield i.e. Zn efficiency index from 92.6 to 80.8% and relative grain Zn uptake i.e. Zn efficiency from 71.9 to 49.7% among the genotypes. On the basis of grain yield and Zn efficiency, genotypes were classified on efficient and responsive (Swarna Sub-1, Rajendra Bhagwati, Sudha, RAU 3055 and Janki), efficient and nonresponsive (BPT 5204-Sub-1, RAU 759, Birsamati, Rajshree and Sita), inefficient and responsive (Kalanamak, Kanak, Sugandha and Jeerabati) and inefficient and non responsive Rajendra Subhashni, Ranvir Basmati, Satyam and Radha. From a practical point of view genotypes that produce high grain yield at low level of Zn and respond well to Zn additions are the most desirable because they able to express their high yield potential in a wide range of Zn availability.