Abstract
Drought is one of the major environmental constraints limiting crop productivity especially in dryland regions. Fifteen maize genotypes suitable for cultivation in rain-fed regions of Pakistan were evaluated for their response under drought conditions. The parameters questioned were relative water content (RWC), osmotic potential (Ψπ), root length (RL), shoot length (SL) and root-shoot ratio (RS-ratio). A comparison for these parameters was made between drought exposed plants and well-watered control plants. A highly significant difference (P≤0.01) between genotypes was recorded for RWC, Ψπ, RL and shoot length. Genotypes NP-3 and EV-77 showed highest retention of water contents (79% and 78%, respectively) after seven days of drought stress, while I. Gold and Rakaposhi had the lowest RWC of 59% and 61%, respectively. A significant overall increase in Ψπ was observed in all genotypes after drought stress, yet genotypes EV-77 and NP3 showed the highest Ψπ of –1.13 and –1.03 MPa, respectively under water deficit conditions. RS-ratio did not differ significantly in all genotypes before as well as after drought stress. NARC-2704 and NP-3 exhibited the longest root lengths of 23.3 cm and 23 cm, respectively in control plants without water stress but increase in their RL after drought stress was not remarkable. Comparisons showed that NP-4 had the highest increase (21.3%) in RL while EV-77 showed 16.3% increase after drought stress. As expected, relative shoot lengths significantly decreased in nearly half of the genotypes after drought treatment, nevertheless, this decrease remained non-significant in the remaining genotypes compared to control well-watered plants. This decrease was more evident in EV-77 (17%) followed by Soan-3 (15%). Collectively, our findings suggest that NP-3 and EV-77 are superior genotypes for the traits investigated under both drought and well-watered conditions, especially, for having high RWC and Ψπ.
Qurat ul Ain, Saad Imran Malik, Muhammad Irshad Ul Haq. (2016) A comparison of the effects of soil water deficit on root and shoot traits of maize genotypes, The Journal Soil & Environment , Volume 35, Issue 2.
-
Views
364 -
Downloads
34
