To generate new breed lines of bermudagrass and reduce management costs of turfgrass, gamma-ray irradiation was used for induction of dwarf mutants from a native bermudagrass (Cynodon dactylon) germplasm. Three dwarf-type mutant lines (7-9, 10-5 and 10-12) were isolated from 3000 irradiated stolons. The data from 3-year greenhouse tests and 2-year field tests indicated that the dwarf mutant lines had lower canopy height, shorter internodes and shorter leaves. The line 7-9 had a similar turf coverage rate to the wild-type control, while the lines 10-5 and 10-12 had a slower turf coverage rate than the wild-type control. Under drought stress, all three dwarf mutant lines maintained higher relative water content and lower ion leakage than the wild type in the greenhouse tests. The field tests showed that the dwarf mutant lines had lower leaf firing during a progressive drying of soil. Our results indicated that bermudagrass mutants induced by gamma radiation exhibited dwarf characteristics and improved drought resistance, which was probably associated with unbalance of plant hormones in vivo.

Ancylostoma ceylanicum is a common zoonotic nematode. Cats act as natural reservoirs of the hookworm and are involved in transmitting infection to humans, thus posing a potential risk to public health. The prevalence of feline A. ceylanicum in Guangzhou (South China) was surveyed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In total, 112 faecal samples were examined; 34.8% (39/112) and 43.8% (49/112) samples were positive with hookworms by microscopy and PCR method, respectively. Among them, 40.8% of samples harboured A. ceylanicum. Twelve positive A. ceylanicum samples were selected randomly and used for cox 1 sequence analysis. Sequencing results revealed that they had 97-99% similarity with A. ceylanicum cox 1 gene sequences deposited in GenBank. A phylogenetic tree showed that A. ceylanicum isolates were divided into two groups: one comprising four isolates from Guangzhou (South China), and the other comprising those from Malaysia, Cambodia and Guangzhou. In the latter group, all A. ceylanicum isolates from Guangzhou were clustered into a minor group again. The results indicate that the high prevalence of A. ceylanicum in stray cats in South China poses a potential risk of hookworm transmission from pet cats to humans, and that A. ceylanicum may be a species complex worldwide.