Comparative Screening of Hybrids and Synthetic Maize (Zea mays L.) Cultivars for Drought-Sensitive and Drought-Tolerant Under Different Irrigation Regimes

Water scarcity is the most serious issue in crop production around the globe. Because of less water availability, various breeding and agronomic management techniques are being used to cope with this issue. For this purpose, a pot experiment was performed to screen hybrids and synthetic maize cultivars for drought-tolerance under various irrigation regimes at green-house of Agronomic Research Farm, Bahauddin Zakariya University, Multan, Pakistan during 2017. Experimental treatments comprise five maize hybrids viz. H1=DK-6317, H2=DK-6724, H3=P-1543, H4=P-1429, and H5= P-1574 and three locally synthetic maize cultivars viz. S1= Neelum, S2= Pak- Afghoi, and S3= Sadaf and three irrigation regimes viz. Control (CK) =80%WHC (water holding capacity), low drought (LD) =60% WHC and severe drought (SD) =40% WHC. It was resulted that irrigation regimes significantly affect growth and plant water relation. Results regarding maize hybrids growth showed that maximum plant height (5.20, 46.8 and 38.77 cm), number of leaves (6.41, 6.19, and 5.65), leaf area per plant (415.5, 361.5 and 305.8 cm2), dry weight of shoot per plant (6.09, 5.09 and 4.39 g) and dry weight of root per plant (0.85, 0.82 and 0.78 g) was obtained from DK-6724 under CK, LD and SD, respectively.  While the minimum plant height (45.23, 36.47 and 28.87 cm), number of leaves (5.38, 5.05 and 4.79), leaf area per plant (11.87, 10.99 and 10.01 cm2), dry weight of shoot per plant (5.71, 4.75 and 4.02 g) and dry weight of root per plant (0.66, 0.63 and 0.61 g) was measured in P-1429 under CK, LD and SD, respectively. Likewise, in synthetic cultivars, Neelum performed well followed by Pak-Afghoi and Sadaf in all irrigation regimes. Results regarding plant water relation revealed that DK-6724 and Neelum maintained their osmotic potential and are considered as drought-tolerant. While P-1429 and Sadaf could not maintain their osmotic potential and were considered as drought-sensitive under normal and drought stress.