Allelopathic interference of alfalfa (Medicago sativa L.) genotypes to annual ryegrass (Lolium rigidum).
Alfalfa (Medicago sativa L.) genotypes at varying densities were investigated for allelopathic impact using annual ryegrass (Lolium rigidum) as the target species in a laboratory bioassay. Three densities (15, 30, and 50 seedlings/beaker) and 40 alfalfa genotypes were evaluated by the equal compartment agar method (ECAM). Alfalfa genotypes displayed a range of allelopathic interference in ryegrass seedlings, reducing root length from 5 to 65%. The growth of ryegrass decreased in response to increasing density of alfalfa seedlings. At the lowest density, Q75 and Titan9 were the least allelopathic genotypes. An overall inhibition index was calculated to rank each alfalfa genotype. Reduction in seed germination of annual ryegrass occurred in the presence of several alfalfa genotypes including Force 10, Haymaster7 and SARDI Five. A comprehensive metabolomic analysis using Quadruple Time of Flight (Q-TOF), was conducted to compare six alfalfa genotypes. Variation in chemical compounds was found between alfalfa root extracts and exudates and also between genotypes. Further individual compound assessments and quantitative study at greater chemical concentrations are needed to clarify the allelopathic activity. Considerable genetic variation exists among alfalfa genotypes for allelopathic activity creating the opportunity for its use in weed suppression through selection.
School of Agricultural and Wine Sciences, Faculty of Science, Charles Sturt University, Building No 286, Boorooma Street, Wagga Wagga, NSW, 2650, Australia. zubair.sau@gmail.com.|Graham Centre for Agricultural Innovation (an alliance between Charles Sturt University and NSW Department of Primary Industries), Wagga Wagga, NSW, 2650, Australia. zubair.sau@gmail.com.
Hasan Muhammad
HM
Zubair
School of Agricultural and Wine Sciences, Faculty of Science, Charles Sturt University, Building No 286, Boorooma Street, Wagga Wagga, NSW, 2650, Australia.|Graham Centre for Agricultural Innovation (an alliance between Charles Sturt University and NSW Department of Primary Industries), Wagga Wagga, NSW, 2650, Australia.
James E
JE
Pratley
Graham Centre for Agricultural Innovation (an alliance between Charles Sturt University and NSW Department of Primary Industries), Wagga Wagga, NSW, 2650, Australia.|Department of Primary Industries, Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, 2650, Australia.
G A
GA
Sandral
South Australian Research and Development Institute, Waite Campus, Adelaide, SA, 5001, Australia.
A
A
Humphries
D064089:Allelopathy; D005838:Genotype; D008129:Lolium / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D000455:Medicago sativa / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D053147:Plant Exudates / Q000737:chemistry / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000502:physiology
D053147:Plant Exudates
Alfalfa; Allelopathy; Annual ryegrass; Bioassay; Inhibition; Metabolomic