The yield potential evaluation of some autumn wheat izogene varieties based on drought sensibility index (DSI) in the conditions of Oltenia South Central area.

One the main important direction in the wheat breeding is the one about the plant’s waist and that the variation in this character. Seen from the agronomical point of view, plant waist is a very important feature, given that there is a direct correlation between this one and the fall resistance. The genetic basis of this phenomenon is determined by the Rht type genes, which are known to breeders for over 50 years and although it was extensively used in wheat research, but this gene can not be transferred to other cereals. In our country, the influence of Rht type genes on the genome of the wheat plant in our specific climatic conditions has been studied in research centers in Şimnic-Dolj, Brasov or Fundulea, but the literature is rather with incomplete results. The objectives of this study was to identify the stability level of the yield potential of isogenic Rht type wheat lines in the specifically soil, geographic and climate conditions area of Oltenia plane, which is well-known for prolonged periods of drought during the summer. Thus, it was applied the formula of Stress Sensitivity Index (SSI) after Fisher and Maurer, two Australian researchers, a formula that takes into account both production in dry years and in years with normal rainfall. Experienced biological material was represented by a set consisting of three isogenic lines of common wheat (Triticum vulgare ssp. aesticum), which had some Rht type gene combinations, in dominant state and recessive state, respectively: - high wheat lines with the rht1r - semi-dwarf wheat lines that have rht1R - semi-dwarf wheat lines that have Rht1&rht8 type genetic combination. The results demonstrated that the organisms that possess Rht type genes have greater sensitivity to adverse conditions, but has a higher production potential under normal precipitation conditions, so that in the event of creating of wheat cultivars with Rht type genes, they can achieve outstanding results in irrigated areas or in less exposed drought areas. Also, when using the Stress Sensitivity Index, this one quantifies the stability of the yield potential, but did notice in a very objective measure the yield potential of organisms.