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Gamma Ray Dosage and Mutation Breeding in St. Augustinegrass 1
Author(s) -
Busey Philip
Publication year - 1980
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1980.0011183x002000020008x
Subject(s) - biology , stolon , mutation breeding , cutting , genotype , mutant , botany , horticulture , genetics , gene
Stolon pieces of St. Augustinegrass [ Stenotaphrum secundatum (Walt.) Kuntze] were irradiated with gamma rays in an attempt to cause mutations. A practical dosage for most genotypes was 4,500 fads. This dosage caused considerable (50%) growth retardation and a mean survival of about 40% of single‐node cuttings. However, ‘Bitterblue’ and another accession were entirely killed at 4,000 rads. At 4,500 rads, up to 7% recognizable mutants of accession FA‐243 were obtained. This proportion resulted when irradiated cuttings were propagated clonally and observed for 1.5 years in replicated microplots. In addition, to morphological variants, a chimeral anthocyanin change was noticed. From this chimera arose a stable genotype with green stolons and white stigmas, whereas the source genotype (FA‐243) had red stolons and purple stigmas. Associated reduction in fertility from 56 to 0.6% suggested that the mutation arose as a small chromosome deletion. Mutation breeding is effective in improving St. Augustinegrass when easily recognizable variants are needed.