Monday, July 25, 2011

The Origin of Crop Plants

The study to know the origin of crop plants is not only subject of great academic interest but it is important also for a very practical reason. I start thinking about this topic when I travel through the Cameroon Highland old road to Tanah Rata on a day visits to Highland Vegetable production area for farm inspection. The crop scientist I believe had a hard work to know the genetic of particular crops to increase crop production and to extend the range of new environments in which important crop can be grown. Plants like rubber (Hevea brasiliensis), Oil Palm (Elaeis guineensis) and Cocoa (Theobroma cacao) are not from Malaysia but it was succesfully grown at our land and become the largest world producers for many decades. This article I would like to share my knowledge on the origin of Crop Plants base on my experience and make some reference to an old Longman Text Book with titled 'Botany of Tropical Crops' recently.

All of our crops was domesticated from our ancestor and have since evolved in cultivation while subject to selection by man. In front of my kampong I able to grow selected sweet corn, edible sweet rambutan (Nephellium spp), Tasty Durian (Durio zibethinus) and other edible food crops. Human domesticated many of this crop for thousands of years as a civilization process. Genetic diversity of crop plants accumulated as the process of migration and through hybridization of cultivars with their wild relatives. Most mutants were probably inferior types and failed to survive this cultivated populations. The superior variety were selected by man and established as their food source and the seeds retain and kept for generations.

Natural hybridization between cultivars and their wild and weedy relatives especially on cereal crops played an important role in the evolution of our crops. There are so many genes and chromosomes knowledge between the crops with different characteristic for plant breeding process. Talk about this the plant breeders work hard to produce new seeds that is suitable for local environments, adaptable to new agronomic practices, resistance to pests and diseases, short harvesting periods and high productivity.

Two kinds of evidence I think will help us to determine and speculate the origin of crop plants. First and the most importance I think is a rare archaeological evidence of the remain of the primitive crops plants and of primitive agricultural communities (especially on their farming tools and the unstensils they use to prepare and cook their foods) provide the only empirical information about the time and place of very early agriculture. The history shown few remain area such as at Western Asia, Zagros mountain, Southern Turkey, Iraq, Iran, Mexico and China. This area are known as 'fertile crescent' for agriculture began some 7,000 - 9,000 years ago. The early crops such as maize, beans, cucurbits, chili peppers indicate the primitive wan long practiced agriculture for their foods supply.

The second chief source of information I think is from the origin and history of plants genetic. The study to relate the new crop plants with the wild species of genetic diversity is to determine how closely related. The Russian botanist known as Vavilov proposed a concept of 'Centres of Crop Origin' in which he introduce a crop domestication program to study their characteristic based on locality. many crops are genetically diverse in regions which could not have been their centers of origin because they are outside the geographically range of the wild progenitors (unless the wild species have become greatly restricted in distribution since the cultivars were derived from them). At this stage I think many of you not really clear the concept introduced by Vavilov from Russia. Do You?

I start think where is the origin of most crop plants today. Is it on the both theory above able to give us more confident. As I go through the books, the main centres of origin of crop plants delineated by Vanilaov and some of them were domesticated as as follows:-

1. CHINA :
Soybean, adzuki beans, Orange

Rice, tea, jute, pepper, Some Phaseolus spp

Sugar cane, coconut, banana and some yams

Wheat , barley, rye, Lucerne, lentil, Chick pea

Cabbage, Lettuce, olive, broad beans.

Sorghum, pearl millet, cowpea , Arabica coffee, finger millet

7. SOUTH AMERICA , CENTRAL AMERICA , ANDES AND SOUTH MEXICO : Maize, some cucurbits, upland cotton, sisal, chili peppers, potato, sweet potato, tomato

Groundnut, cassava, cocoa, rubber and pineapple.

I hope the article provide some information for all readers. I think the crop plants established for human and animal consumption are created and studied for thousands years ago. The latest technology with scientific research able for us to ensure the crop plants is no more grown in the origin of the plants.

M Anem
Muar, Johor,

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