Abstract only

At Gory experimental station of Georgian RI of Agriculture we studied the single and additive effect of chemical and physical mutagens on local grain and pod varieties of haricot -Field Red, Khetagurovi-4, Ksani, local landrace, Berbuki and Gori varieties. Significant variability of morphological and biological characteristics was observed in the first generation, expressed in the change of plant height and extension of vegetation period and other bio- logical traits of the plant. Different effects on vege- tation period of plants at different rates of mutagenic treatment were ascertained. For example, in grain varieties vegetation period was shortened by 10-12 days, however, significantly late flowering was observed in some variants (check 78 days). At ir- radiation with lO kR plant height decreases by 3-5 cm, the same effect is recorded at high irradiation rates (20 kR). In orchard varieties (Berbuki and Gorl) plant height reduction was recorded, however, irradiation with 10 kR had stimulating effect of some plants in Berbuki variety. At combined mutagenic treatment with gamma irradiation and nitrosomethyl urea (NMU) 5- 7 days late flowering with the subsequent early maturing was recorded. Flower color, number of inflorescences and number of flowers per inflo- rescence were changed. Separate plants developed multiple pods on single pedicle (15 kR + 0,03% NMU). Plants with increased number of pods compared to check or absolutely sterile individual plants were recorded in all monitored varieties. Correspondingly, fertility level was lowered,. ho- wever, these plants are subject to significant variability based on variety origin and genotype stability. Variation of yield in the first generation as- certained increase in number of sterile plants at in- creased rates of mutagenic treatment. Maximum rate of sterility (85,6% and 91,9%) was recorded at high treatment rates (15 kR + 0,03% NMU and 20 kR+0,03%NMU). The lowest fertility rate of 85,6% was re- corded for the local landrace. Gori with the rate of 91,9% (20 kR) and Field Red with the rate of 96,0% (20 kR) are close to the check i.e. these varieties are less variable in fertility compared to the rest of the studied varieties. Variability rate increases with the increase of treatment rate and reaches its maximum 23,9- 25,6% at 20 kR and 20 kR + 0,03% NMU in the local population and variety Ksani (1997.). Low variability was recorded for Gori and Field Red varieties (1,2-1,3% at 0,01 % NMU and 3,3-3,5% at 10 kR). Additive mutagenic effect was studied ín Ksani and Gori varíetíes. Increased rate of mutagenic treatment brings about increase of variability frequency in both varieties, however, Gori variety proved to be more stable in this characteristic as well, showing variability rate of 5,0% at treatment rate 15 kR + 0,01% NMU, compared to 10,4% variability rate recorded for Ksani variety. At higher treatment rate 15 kR + 0,03% NMU the above values were 17,1% and 20,3% for Gori and Ksani varieties, respectively. Tests have ascertained that the single and additive effects of gamma irradiation and NMU stimulate the variability of characteristics determining productivity, while the frequency of morphological variability correlates with the rate of mutagenic treatment (radiation dose and chemical concentration).

English

0409|AGRIS 0401|AL-Wheat Program

Juan Carlos Mendieta

CIMMYT Publications Collection