Ketahanan Tanaman Karet

Analisis Genetika Pewarisan Sifat Ketahanan Tanaman Karet terhadap Penyakit Gugur Daun Corynespora
Genetic Analysis of Corynespora Leaf Fall Disease Resistance in Hevea Rubber*

Corynespora leaf fall disease (CLFD) caused by Corynespora cassiicola fungus is one of the most important diseases of Hevea rubber in Indonesia. The fungus infects rubber leaves of all ages of susceptible clones all year long irrespective of weather conditions. Chemical treatment to control CLFD rubber is not effective. The strategy to contol CLFD should be emphasized on the use of resistant plant materials. However, resistant rubber clones to CLFD tend to be broken by new virulent strains of the fungus. Therefore, the breeding program of Hevea rubber for CLFD resistance has to be directed to create new rubber clones carrying durable resistance character. The objective of the research was to study genetic inheritance of the resistance character of Hevea rubber to CLFD. F2 population, generated from F1 rubber clones of PR 255, PR 303, PB 260, RRIC 100, and RRIM 712, were analyzed at Balai Penelitian Karet Getas, Salatiga. The result indicated that resistance character of rubber to CLFD was controlled by two major genes. Genotypic models for the resistance traits were A-B-, e.i. AABB, AABb, AaBB and AaBb, the moderate genotype were AAbb and Aabb, and the susceptible ones were aa—, e.i. aaBB, aaBb or aabb. Recessive forms of A gene supressed the expression of the second gene B/b.

sumber : Hayati Journal of Biosciences