Premium
Cotton Resistance to Root‐Knot Nematode: II. Post‐Penetration Development
Author(s) -
Jenkins J. N.,
Creech R. G.,
Tang B.,
Lawrence G. W.,
McCarty J. C.
Publication year - 1995
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/cropsci1995.0011183x003500020013x
Subject(s) - biology , meloidogyne incognita , root knot nematode , nematode , inoculation , horticulture , gossypium hirsutum , fiber crop , loam , terra incognita , botany , soil water , ecology
Root‐knot nematode (RKN), Meloidogyne incognita (Kofoid and White) Chitwood, damages cotton, Gossypium hirsutum L., roots, affecting water and nutrient uptake and predisposing the plants to other soilborne pathogens. Post‐penetration development of RKN was compared on three genotypes. Susceptible M‐8, moderately resistant M‐78, and highly resistant M‐315, were grown in a greenhouse in a Wickham sandy soil (a fine, loamy, mixed thermic, Typic Hapludult) and inoculated with second‐stage juveniles. RKN in each of 7 developmental stages were counted every 2 d for 44 d. At 18 DAI, 70, 45, and 6% of RKN present were adults in M‐8, M‐78, and M‐315, respectively. In addition to slower development of RKN in M‐315, resistance is expressed by significantly fewer developing third and fourth stage juveniles at 8 DAI and fewer developing to mature females at about 24 DAI. Most RKN that penetrated M‐315 failed to establish and/or maintain giant cells. However, a few females established giant cells. At 44 DAI, the numbers of egg‐laying females on M‐8, M‐78, and M‐315 were 299, 144, and 5, respectively. There were significantly fewer root galls on M‐315 than on M‐78 or M‐8 beginning 10 DAI, and significantly fewer on M‐78 than on M‐8 at 40 DAI. Galls were significantly smaller on M‐315 than on M‐78 or M‐8 beginning 8 DAI, and significantly smaller on M‐78 than on M‐8 beginning 18 DAI. Thus, the post‐penetration development of root‐knot nematode was slower, fewer developed to adult females, and root galls were fewer and smaller on the resistant genotypes than on the susceptible M‐8.