000			02269nam a2200241Ia 4500
008			220216s9999 xx 000 0 und d
100			_aAchuo Enow A
245		0	_aIn-vitro evaluation of exotic Hevea genotypes for resistance to corynespora cassiicola
260			_bJournal of Rubber Research _c2001
300			_a255-269
520			_aHevea leaf fall disease caused by Corynespora cassiicola (Berk & Curt) Wei, is one of the major disease constraints to the production of natural rubber (Hevea brasiliensis) in South Cameroon. Attempts to control this disease by traditionally recommended practices such as artificial defoliation or aerial spray of fungicides have not yielded satisfactory results in Cameroon. Production of disease resistant planting material may provide a more efficient disease control strategy. As part of a screening process of a large pool of Hevea genetic resources for disease resistance, we evaluated in-vitro, 28 genotypes collected from Amazonia. These genotypes were tested for resistance to two isolates of C. cassiicola (NKO1 and NKO2), obtained from different clones showing different levels of susceptibility to the disease in the same field in South Cameroon. The two isolates had similar growth characteristics on culture media. However, isolate NKO1 grew faster than NKO2 on Ptato Dextrose Agar and was also more virulent on the test material. The two isolates may belong to different races. To verify this, further characterisation of the isolates is recommended. Significant differences were observed in the response of the tested Hevea genotypes to each of the isolates. Genotypes AC/S/12/22, RO/07/48, and AC/B/19/22 had the highest resistance to both isolates. These could constitute good source material in breeding for disease resistance. Due to their high susceptibility to both isolates, genotypes AC/S/12/02, MT/1/25, MT/C/04/22, MT/C/04/27 and RO/C/08/33 may have to be avoided in any such breeding programme.
650			_aBreeding
650			_aCameroon
650			_aCorynespora cassiicola
650			_aDisease resistance
650			_aGenotypes
650			_aHevea brasiliensis
650			_aIn vitro
650			_aLeaf fall
700			_aEbai Maxwell M
700			_aMokoko Gobina S
942			_cJS
999			_c61664 _d61664