Ultra Morphology of Flower, Phenology and Breeding System in a Monoecious plant, Euphorbia hirta L.

Radhika A.

Department of Botany, Catholicate College, Pathanamthitta, Kerala 689645.

Dr. Giby Kuriakose

Assistant professor, PG and Research Department in Botany, Sacred Heart College, Thevara, Kochi-13

Abstract

Ultra-morphology, phenology and breeding systems in Euphorbia hirta L. were analyzed using systematic experimentation for the very first time. These aspects are important to assess the pollination mechanism and reproductive strategies of flowering plants. Since it is a monoecious plant, information on Euphorbia hirta L.'s phenology, structural arrangements and breeding system might help in better understanding its reproductive biology. Cyathium is the characteristic inflorescence of the genus Euphorbia, resembling a single flower. Structural organization of cyathium is complex, with a centrally situated, reduced female flower (represented by a single pistil) surrounded by a few male flowers (represented by stamens). The pollen is dicolpate, diporate and possibly of bilateral type, with two-celled pollen grains that are linear in shape, and pittings and articulations on the exine wall. The f lowering period (anthesis), anther dehiscence, the functional period of androecium and andgynoecium, etc. were recorded. Fruit set under open-field conditions was recorded to be high, almost 100%. This is found to be a result of high fruit set in both inbreeding (geitonogamy) and outbreeding (xenogamy). However, apomixes resulted in significantly low fruit set when compared to other breeding experiments.

Keywords: cyathium, pollination, phenology, breeding