Full Lenght Research Paper

Screening for drought tolerance in maize (Zea mays L.) hybrids at an early seedling stage

Abdul Qayyum*, Shahzad Ahmad, Shoaib Liaqat, Waqas Malik, Etrat Noor, Hafiz Muhammad Saeed and Memoona Hanif

Department of Plant Breeding and Genetics, University College of Agriculture, Bahauddin Zakariya University,

Multan, Pakistan.

*Corresponding author. E-mail: raoqayyim@bzu.edu.pk.

Accepted 3 April, 2012

 Abstract

Drought stress is an abiotic factor affecting growth badly and ultimately, yields of crop plants. The current study was planned to explore the variations and determine the performance of target traits under drought conditions. Six seedling characters; that is, number of crown roots, number of seminal roots, primary root length, number of lateral roots, fresh root weight and dry root weight were evaluated under three moisture levels. On the basis of mean values, hybrids of tropical yellow H₃, H₄, H₈, H₁₁, H₁₅, H₁₉ and highland yellow H₂₇, H₂₉ showed best performance under the drought conditions. Principal component analysis was also used to assess the contribution of major traits which were attributing maximum variations among maize hybrids. The first two components with eigen values greater > 1 contributed 76.94% of the variability among the hybrids. The PC-1 was related to the number of seminal roots while the PC-2 was related to the number of crown roots and number of seminal roots. The magnitude of broad sense heritability was high for all the traits. It suggested that all traits were genetically determined and there is an ample scope for the improvement of these traits by selection and breeding.

Key words: Drought stress, heritability, genetic diversity, principal components analysis.