Genetic diversity for physiological deterioration in cassava roots.
Iglesias, C.; Bedoya, J.; Morante, N.; Calle, F.;
Tropical tuber crops: problems, prospects and future strategies. Year: 1996 Pages: 73-81 Ref: 11 ref.
1996
บทคัดย่อ
Cassava [Manihot esculenta] roots are characterized by rapid post-harvest deterioration (PHD). The available genetic variability in elite cassava clones was evaluated in different ecosystems at 3 sites in Colombia (Palmira, Villavicencio and Media Luna) during 1991. Non-damaged roots were evaluated each day between the second and eighth day after harvest (DAH). Roots were cut to 14 cm, the distal part was covered with plastic and the percentage deterioration was evaluated in each of 7 transverse sections of 2 cm. Root to root variability was relatively large and depended on the clone being evaluated and the site. The majority of the clones evaluated at Media Luna and Villavicencio showed a linear trend when relating PHD to DAH, whereas at Palmira about half of the varieties adjusted to a quadratic model. Genetic variability on the last day of evaluation (8 DAH) accounted for 52% of the total observed variability, suggesting the possibility of genetic progress in a selection programme. It is thou
ght that clones with high levels of deterioration (CM3306-5 and CM5253-4) will be crossed with those presenting reduced levels (CM4484-2 and MCOL1505) to build up genetic stocks to study intrinsic biochemical processes responsible for PHD. MCOL2215 gave differential performance across evaluation sites and is thought to represent a valuable material for studying environmental effects on PHD.