SYSTEMATIC STUDIES ON SOME SPECIES OF Brassica

Abstract

The Brassicaceae are one of the more sharply defined and readily recognizable large families of plants. In counterpoint, the genera are ill-defined and frequently confluent. Thus, any new botanical information about Brassicaceous genera are urgently to be welcomed.

Dealing . with the genus Brassica, the present study is confined mainly to the oilseed crops, namely,. Brassica napus L. (oilseed rape), Brassica campestris L. (turnip rape), . Brassica juncea (L.) Czernajew (Indian mustard). A taxonomic study was carried out for the sake of proper delimitation and identification of Brassica throughout a detailed phytography study dealing with morphological, histological, chemical and molecular characters.

The field work was carried out in the Agricultural Experiments and Researches Station, Faculty. of Agriculture, Cairo University, Giza, Egypt. during two successive seasons of 2002/2003 and 2003/2004. Date of cultivation was October 30th, inboth seasons. Results obtained could be summarized as follows: 1• •The fruit of studied species is a silique, linear in shape, about 5 to 8 em. in length, and brownish in colour. Seeds of oilseed ...: rape and Indian mustard are small in size and blackish in colour. But seeds of the turnip rape is small in size and brownish in colour. Germination of studied species is epigeal with percentage of99% in oilseed rape, 92% in turnip rape and 98% in Indian mustard. 2. The root system of the 3 species is composed mainly of a stout tap root with a large number of lateral roots, developed acropetally in 2 longitudinal rows and do not branch. The root system is ivory in colour. 3. As the seedling stage of studied species came to an end, being 14 days after sowing, internodes were too short to be• detected easily.