Taxonomic Description and Reproductive Behavior of Giant Pangola (Digitaria valida Stent)

Abstract

The chromosome number and reproductive behavior of Giant Pangola, a type of Digitaria valida Stent, were determined to evaluate the possibility of using it in a breeding program. It was also described and verified taxonomically. The observations revealed anomalies which would appear to severely handicap its use in breeding. The somatic chromosome constitution of 42 is different from those previously reported for this species. Microsporogenesis was irregular in all cells studied, characterized by multivalent formation, lagging univalents, and micronuclei, and resulted in only 2.3 percent of the pollen grains staining completely in IKI solution. No degeneration was observed during megasporogenesis but was usually apparent after megaspore formation. It is concluded that the chromosomal irregularities noted may be sufficient to cause the very low seed set and that this low fertility will limit the utilization of Giant Pangola in a breeding program.