Abstract

TETRACARPELLARY OVARY IN BRASSICACEAE -A CASE STUDY WITH YOUNG FRUITS OF RAPHANUS SATIVUS L. VAR. CAUDATUS ALEF. (RAT TAIL RADDISH)

Mammen Daniel*

ABSTRACT

Anatomical studies of the young fruits of Rat tailed raddish (Raphanus sativus L. var. caudatus Alef) revealed that the gynoecium possesses 2, 3 or 4 carpels. The prevalence of 2 carpelled condition indicates that to be an advanced state and 3 as well as 4 – carpels as primitive traits. Since Raphanus is a primitive taxon, it is inferred that the gynoecium of Brassicaceae is basically tetracarpellary as suggested by many earlier taxonomists and the 2-carpelled condition arose by the progressive sterilisation of two carpels seen on both the sides of central fertile carpel having ovules (seeds in fruits). In addition, there were bract like appendages inserted in the pericarp at the base of fruits and their number also varied from 2 to 4 depending on the number of carpels. These appendages appeared exactly similar to the fruits in having pericarp, placenta like regions and a central cavity and can be considered as sterile carpels retained in fruits.

Keywords: Raphanus sativus L. var. caudatus, Fruit anatomy, Brassicaceae, Tetracarpellary Gynoecium, Bract like appendages.