Vegetos

Abstract

Rice (Oryza sativa L.) is the “Global Grain” because of its use as prime staple food in about 100 countries of the world. Aerobic rice provides for effective use of water as the concept of flooding paddy fields is abandoned in this ecosystem. But due to the transition from flooding of paddy fields to aerobic system of rice cultivation many factors that determine nutrient (Zinc) bioavailability changes in addition to water deficit. Achieving high yields under aerobic conditions requires new varieties of “aerobic rice” combining both the water stress tolerance and nutrient (especially Zinc) deficiency tolerance traits. The present study was undertaken to know the genetic and molecular basis of zinc (Zn) deficiency tolerance using an indica/indica F₄ RIL population of CO51 (A high yielding low land variety with low zinc efficiency) and CB-06-803-2 (An improved upland culture with high zinc efficiency) comprising of 246 RILs. These RILs were phenotyped under aerobic system in control (+Zn) and stress (−Zn) plots and genotyped using 80 SSR markers specific to zinc transporter genes (ZIP family) and root related traits. The parents for the mapping population were selected by screening 60 rice germplasm lines for ZE under aerobic condition. The reported map position of gramene database was used to estimate the QTLs and followed inclusive composite interval mapping of additive and dominant (ICIM-ADD) method. The QTL analysis resulted in the identification of three QTLs viz., zinc efficiency in shoot (ZES), days to 50 per cent flowering in control (DFFC) and shoot zinc content in stress (SZCS) condition.