M1 cytogenetic and physiological effects of gamma-rays in Sudan grass (Sorghum sudanense (Piper.) Stapf)

I. Golubinova, K. Gecheff

Abstract: This paper presents data from investigations concerning the chromosome damage and physiological effects in the first generation (M1) of gamma-irradiated dry seeds of Sudan grass (Sorghum sudanense (Piper.) Stapf.), which is part of a study devoted to the assessment of the potential of a wide range of doses (100, 200, 300 and 400 Gy) of this mutagenic agent in inducing genetic changes in this crop. Three varieties of different origin, namely, Kazitachi (originating from Japan), Vercors (USA) and Voronejkaya (Russia) were subjects of our investigation. The anaphase analysis of the chromosome aberrations did not reveal significant differences in the radiosensitivity of the varieties studied Voronejkaya being however most resistant at the highest dose. The influence of gamma rays on three physiological parameters (germination, survival and sterility) of M1 progeny of the varieties used were investigated The data showed clearly pronounced “dose effect”; with increasing dose the values obtained for each of these biological parameters decrease and the differences are statistically proven. Survival data followed similar trends as those for field germination. The radiosensitivity of the cultivars is well expressed with the values of LD50, which were calculated on the basis of M1 plant survival. This value is lowest for Kazitachi (307.52 Gy) while LD50 for Vercors and Voronejkaya 9 are 342.63 Gy and 340.97 Gy, respectively. These data provide valuable information when the optimal doses should be chosen for the purpose of mutation breeding programs of Sudan grass varieties.

Keywords: chromosome aberrations; dose effects; gamma-rays; M1 physiological damage; Sorghum sudanense

Date published: 2019-10-16