POD NUMBER AND PHOTOSYNTHESIS AS PHYSIOLOGICAL SELECTION CRITERIA IN SOYBEAN (GLYCINE MAX L. MERRILL) BREEDING FOR HIGH YIELD
ABSTRACT: Field studies were
conducted in two years using 638 F2 and 1185 F3 lines of selected 16 F1 and 15
F2 parent lines (³80 pods plant-1) to evaluate pod number and CO2 exchange rate
(CER) as selection criteria. Pod and seed number, and seed weight of individual
lines were observed during harvesting time, and CER of randomly selected 32 F2
and 30 F3 lines was measured at initial seed filling stage. The selection of F2 lines based on pod number
to generate F3 lines increased the average of seed yield by 39%, and pod number
by 77% in F3 lines compared with F2 lines. A close relationships was found
between seed weight and pod or seed number per plant. Net CER responded sensitively to a reduction
of light in a short-term and showed 78% of F2 lines and all F3 lines with
maximum CER (Pmax)³20 mmolCO2.m-2.s-1. The ratio of pod number per plant and
Pmax varied between lines and were used to group lines resulting in close relationships
between Pmax and pod number. It is concluded that the use of pod number and CER
(Pmax) as selection criteria offers an alternative approach in soybean breeding
for high yield.
Author: S.M. Sitompul, Dian
Indra Sari, Erna Krisnawati, Rachmad Harri Mulia, M. Taufiq
Journal Code: jppertaniangg150029
