EVALUATION OF TURKISH MAIZE HYBRID LINES LEAF GROWTH FOR DROUGHT AND CHILLING TOLERANCE

Abstract

Maize (Zea mays L.) is a drought and chilling-sensitive species required well-watered condition and relatively high temperature for optimum growth and higher yield. In cool climate, maize cultivation is done late planting to avoid early spring low temperature and breeding for early-maturing maize hybrids. As to in the hot climate, round up growth of maize is successful by planting drought resisted lines. However, breeding programs is required many crosses and then screening making the studies time and effort consuming. Therefore, the main goal of this study was to evaluate the Turkish hybrid maize lines for different environmental stresses such as drought and chilling during seedling stages in the greenhouse and growth chambers respectively. Thus, fast and least effort screening methodology is suggested to breeding programs crucial for sustainable agro-biotechnology. Initially, fifteen hybrid maize seedlings were exposed to drought and chilling stresses and also grown under control condition for comparative analysis by separately. Then, growth parameters such as leaf length, leaf elongation rate, leaf width, mature cell size, cell production for leaf 3 and leaf 4 and chlorophyll amount after drought treatments was measured at morphological and cellular level. Finally, kinematic analysis was performed and lines are sorted as tolerant and sensitive according to growth retardation and developed stress symptoms degrees. The results showed that each genotypes reveals different stress tolerance degree under separate treatments. Drought stress treatment showed exceed watering is not association with better growing even plants adapted to less watering condition is more tolerant to drought. The results suggest that stress tolerance is controlled by different genetic factors according to growth stages and stress types. Consequently, breeding for several abiotic stresses would be misleading and each trial should be considered separately. Finally, growth chamber screening would be of great advantage for breeding programs prior to field trial by the higher reproducibility and time reduction.