Dwarf Mutant Induction by Irradiation of Gamma-ray in Korean Lawngrass (Zoysia japonica)

Eun-Ji Bae*   Chung-Yeol  Kim   Jun-Hyuck  Yoon   Chang-Hyun  Sung   Eon-ju  Jin   

1Forest Biomaterials Research Center, National Institute of Forest Science, Jinju 52817, Korea

Abstract

This study was carried out to induce and select zoysiagrass mutants having dwarf traits by using gamma-irradiation. In 2010, CJ4017, which has a large amount of inflorescence, was selected among the Korea lawngrass genetic resources collected from cultivation field. After self-fertilization of the selected individuals in 2015, the harvested seeds were treated with gamma-ray in dose ranges of 0, 25, 50, and 100 Gy for 24 h in 2016 The seeds were germinated in conditions of 8 hours light at 35℃, and 16 hours dark at 20℃ according to standard seed testing method. Seedlings were transplanted into pots, and then grown until growth measurement in a greenhouse. From October 2016 to May 2019, morphological characteristics such as plant height, length of leaf blade, height to lowest leaf were investigated. The plant height and height to lowest leaf of randomly sampled 70 individuals that were gamma-irradiated were shorter by about 1.2 and 1.8 times than those without irradiated gamma-irradiation, respectively. There was no significant difference between doses of gamma-irradiation for those 70 individuals in each dose. Twenty-two dwarf-type mutants were selected, and three-year morphological characteristics were examined to determine if dwarf traits were maintained. An MZ016, which was irradiated with gamma-ray at 50 Gy, was identified with dwarf characteristics plant height. The plant height of the ' MZ016(Sedan)' mutant was 5.9 cm, which was about 3.4 times shorter than the 20.3 cm of the control plant, and it is expected to be used as a low-maintenance by reducing cost of mowing.

Figures & Tables

Fig. 1. Morphological characteristic of natural selection CJ4017 and mutated ‘Sedan’ variety of Korean lawngrass derived from gamma-irradiation (CO). A: Shoot growth of CJ4017 and ‘Sedan’. B: Plant height of CJ4017 and ‘Sedan’.