Kabakta (Cucurbita spp.) yeşil aksam ve kök bölgesindeki iyon dağılımının tuz stresine toleransın belirlenmesinde kullanım olanakları üzerinde bir araştırma

Abstract

It was worked that there were some differences in salt-tolerance between the genotypes and in which parts of seedlings the ions accumulates under salt stress. For that purpose, 26 squash (Cucurbita pepo L., C.moschata and C.pepo var. styriaca) genotypes which were derived from different regions of Turkey were treated with salt stress on their body and then their damaging levels were defined and genotypic difference was proved. Additionally, to be informed about the mechanism of the tolerance towards salt stress and, to explain the functions of ion distribution in arising of tolerance are another aim of the work. When the cotyledon leaves of seedlings which were derived from squash seeds germinated in Vermiculite become to horizontal position, they were taken to hydroponic culture in ½ Hoagland solution of nutrient. After each squash seedlings had at least three leaves (in about 2 weeks), 100 mM NaCl was added in solution of nutrient for 2 days by gradual rising and measurement and analysis were made on 4th and 7th days of salt treatment. Control group plants were continued to be grown in ½ Hoagland solution of nutrient. The concentration of Na+, K+, Ca+2 and Cl- ions, damaging index value, wet weight of plant were measured. Ions were measured on root, stem and the third leaf of backward of apical part. Along with the differences between the genotypes, on each two measurement time, generally, it was observed that Na ion accumulated at least in leaves, secondly in roots and utmost in trunks. K and Ca ions were at least in roots, secondly in trunks, utmost in leaves. Cl ion was utmost in trunk, secondly in leaves and at least in roots. It was observed that making interpretation on the seedlings for selection of tolerant genotype, according to the levels of accumulation between the bodies, would not come up with right results. With the aim of selection of tolerant genotype, the suggestion of that investigation of lower level salt treatment on long-term cultivated plants was discussed. Besides, in comparison with other squash types, İskenderun-4, AB-44, A-20,A-19, Ç-4, Ç-3, Ç-5, Ç-8 and A-3 genotypes showed that more tolerance towards salt.In case Nevşehir-1, Ç.Ü.-7, Ç-9, A-11, A-16, A-32 genotypes were affected in a short time and excessively by salt.