000			02078nam a2200205Ia 4500
008			220216s9999 xx 000 0 und d
100			_aGobina M S
245		0	_aField evaluation of Hevea clones for leaf disease resistance
260			_bProceedings of IRRDB Symposium 1999, Hainan, Peoples Republic of China. pp.91-106.
520			_aA study is going on in the Southern part of Cameroon, where about 50;of Cameroons rubber is planted, to evaluate the resistance of new genetic material, including some traditional clones, to two major leaf diseases (Colletotrichum gloeosporioides and Corynespora cassiicola). This area is characterised by a bimodal rainfall pattern. Results over five years indicate significant differences in the susceptibility of the testes clones to both diseases. For most of the clones, there was no significant differences in the susceptibility of the two diseases. However, the severity of Corynespora was generally higher than that of Colletotrichum. There was also a significant variation in disease severity from one year to another for most of the clones, with a tendency to increase over the years. The general incidence of leaf disease diseases was highest in RRIC 110, PR 228, GU 1276, RRIM 706, GU 198 and MDX 98 while MDF 72, RO 58, MDF 362, MDX 17, RO 46 and RO 42 showed the most resistance. Meanwhile, GU 4673 showed high susceptibility to Colletotrichum, but was appreciably tolerant to Corynespora. This study suggests that, clones such as MDF 72, RO 58, MDF 362, MDX 17, RO 46 and RO 42, by virtue of their resistance to leaf diseases, may constitute a good genetic base for development of new clones. Meanwhile, RRIC 110, PR 228 and GU 1276, by virtue of their susceptibility, especially to Corynespora may have to be avoided in a breeding programme.
650			_aColletotrichum gloeosporioides
650			_aCorynespora cassiicola
650			_aDisease resistance
650			_aHevea brasiliensis
650			_aLeaf diseases
650			_aSecondary leaf fall
700			_aAchuo E A
700			_aChuba P N
942			_cJS
999			_c59380 _d59380