Studies of Morphological Characteristics and Production of Seeds Weeds of Species of Family Brassicaceae (Cruciferous) in Setifian High Plateau, Algeria

Abstract

Aims: The study of production and morphological characteristics of seeds allows identifying the different seeds mixed with cultivated plant; it also allows knowing the various species of weeds in fields. So such studies help to develop different strategies to control weeds. Methodology: The work on the identification starts by collecting seeds from fields then study it thoroughly in the laboratory where researchers often observe it by naked eyes, in addition to the reliance on references and researches concerning describing seeds to make the study effective and successful it must be conducted carefully with continual vigilance because of the smallness of some seeds so we use magnifying glass, the optical microscope  and pocket lamp to see the different external parts of seeds. Results: Generally, members of the species Brassicaceae have small seeds with mostly less than 4 mm long. Seeds can have appendages or not. The seed shape among the investigated species showed wide range of variations. Most of the seeds vary from globose to oblong or oval. The largest seed size is 2.8-3.5 x 0.7-1.1 mm in oval and globose seeds. Seed surface may be smooth, glabrous, or rough that can be useful for identifying species.The seed colour varies from dark reddish,brown to golden red-brown, reddish-brown to dark brown,yellow dark to brown,yellow,shiny brown,Brown dark to black,range-rown, red-brown, grey, black. The production of seeds varies depending on the culture in which the weed grows. Seed production was determined for 10 weed species of Brassicaceae. Studies on seed production potential in Capsella bursa-pastoris, Conringia orientalis, Diplotaxis erucoides and Diplotaxis virgata showed that each plant produces an average of 2500±480, 7800±627, 2200±308 and 3600±48 seeds respectively. Hirschfeldia incana produces  14000±279 seeds /plant whereas Neslia paniculata produces 1540±526 seeds/Plant. One isolated Sinapis arvensis plant can produce over 1200±398 seeds. Thus Rapistrum rugosum produced 280±17 seeds per plant. Conclusion: Seeds morphological description is related to external description of seed, weeds seeds show very big differences as well as seeds of the same species which also can show many morphological differences. The ability to produce seeds with different degrees of dormancy is, most probably, a mechanism by which species of Brassicaceae as other weed species adapts to new environmental situations and ensures its survival by facilitating the dispersal of its seeds in time and space.