Mehmet Atak

Interaction between seed size and NaCl on germination and early seedling growth of some Turkish cultivars of chickpea (Cicer arietinum L.)

Chickpea is an important food legume crop of Turkey and is largely grown for human consumption on low moisture or salt-affected soils. The objective of the study was to find the effects of NaCl stress at electrical conductivities of 4.5, 8.6, 12.7 and 16.3 dS/m and seed sizes (7, 8 and 9 mm) on germination and early seedling growth of three popular chickpea cultivars (AKN-97, Gokce and Uzunlu-99). Mean frequency of germination, germination time, germination index, root length, shoot length and seedling fresh weight showed seed size-dependent responses of cultivars to salt stress. In general, small seeds germinated and grew more rapidly compared to medium and large seeds of the same cultivars against all levels of salt stress, with the best results in cultivar Uzunlu-99. No effect of NaCl treatments was observed on frequency of germination; however, a drastic decrease in early seedling growth was recorded at increased NaCl concentrations. Regression analysis results showed a significantly positive relationship (P<0.01) between seed size and mean germination time, whereas a significantly negative relationship was recorded between seed size and germination index, root length, shoot length. Moreover, linear regression values apparently confirmed that increased seed size in each cultivar affected decreased germination index, root and shoot lengths with enhanced mean germination time. Thus, it was concluded that the use of small seeds could considerably reduce the production costs of chickpea in salt-affected soils.

Effect of age on somatic embryogenesis from immature zygotic embryos of 5 Turkish triticale genotypes

Triticale is an important cereal crop grown throughout the world. The study reports somatic embryogenesis from immature zygotic embryos of 5 Turkish triticale genotypes. The explants were initially cultured on MS medium supplemented with 2 mg dm-3 2,4-D, 500 mg dm-3 glutamine, 100 mg dm-3 casein hydrolysate, 2% sucrose and 7% agar for two weeks in the dark. The temperature was maintained at 24±2oC. Thereafter, the developing embryogenic calli were transferred to MS medium without 2,4-D to achieve embryogenesis under light intensity of 30 000 lux in 16 h light 8 h dark photoperiod at 24±2oC for 2 weeks. The developing somatic embryos were then transferred to MS medium to mature them and obtain plantlets. The highest number of 9.63 somatic embryos per explant were recorded for genotype LAD388 from 14 - 16 days old explants. The experiment clearly established that 14 - 16 days old explants were superior compared to 17 - 19 days old explants in terms of number of somatic embryos per explant. The matured plantlets were acclimatised in the greenhouse on organic matter rich soil mix contained in pots.