Genetics and genetic engineering has played an important role in improvement of plant production. There are following role of genetics in plant improvement.
Role of Genetics in Production of Polyploid Crops
The techniques of genetics for producing polyploid crops have improved the yield of crops. Today most of major crops like wheat, corn are polyploid. Wheat is hexaploid. It has increased the yield of wheat. The new varieties of wheat introduced the concept of green revolution. Green revolution has dramatically improved the production of grains. Thus, it reduced hunger and fatigue on the earth.
It is a traditional technique. The crossing of different varieties of plants species is called hybridization. Hybridization is used to produce plants with desirable traits. Vegetative propagation is performed on hybrid plants. It produces large number of identical plants with these traits.
The plants with foreign DNA are called transgenic plants. Many new genes are introduced into different types of -plants. It has introduced many new characters in plant. It helps a lot in improving the yield and quality of crops. In 1999, transgenic crops were planted on 70 million acres worldwide. The acreage is expected to triple in five years.
Role of Genetics in Producting Insect and Herbicides Resistant Plants
Cotton, corn, potato and soybean plants are engineered. These plants are resistant to insect predation or herbicides. Some corn and cotton plants are both insect and herbicide resistant. These plants are environmentally safe. These crops are resistant to a broad-spectrum herbicide. But weeds are not resistant to herbicides, Thus the herbicides kill the weeds but do not kill the crops. Therefore, weeds are easily controlled by herbicides. It does not need tillage. Thus, it also minimizes the soil erosion.
Improvement in Quality of Food
It is one aim of genetic engineering. Genetic engineering is used to produce crops with improved food quality traits. Examples:
(a) Transgenic soybean is developed. This soybean produces monounsaturated fatty acid oleic acid. It is a big change. It can improve human health.
(b) Genes were derived from Vernonia and castor bean seeds. These genes were transferred into the soybean genomes. These altered plants also produce vernolic acid and ricinoleic acid. These are derivatives of oleic acid. Vernolic acid and ricinoleic acid are used to harden the paints and plastics.
Salt Tolerant Plants
Genetic engineers have developed a salt tolerant plant Arabidopsis. It has following steps:
(a) The scientists identified a gene coding for channel proteins. These proteins transport Na+ and H across a vacuole membrane. Na+ ions are stored in a vacuole. Thus Na+ does not interfere into plant metabolism.
(b) The scientists cloned the gene and used these genes in genetically engineered plants. These plants overproduce the channel protein.
(c) The modified plants grow well in water with a salty solution. Irrigation causes salinization of soil. It reduces crop yields. Today crop production is reduced by 50% of due to salinization. This problem is solved by producing salt tolerant crops. Production of salt, drought and cold tolerant crops can increase the agricultural yields. It will reduce the need of more farm acreage. It will provide enough food for world population. The population expected to be become nearly double by 2050.
Genetic Engineering is trying to increase productivity. Following steps are taken for this purpose:
(a) C4 cycle is being introduced into the rice. The C4 cycle uses a different method of capturing CO2. So C4 cycle reduces the inefficiency of RuBP carboxylase.
(b) The structure of stomata can be changed. It can increase carbon dioxide intake or cut down water loss.
(c) It can increase the efficiency of the enzyme RuBP carboxylase, RuBP captures C02 in most plants.
Production of Human Products from Plants
Single gene transfers have allowed plants to produce various products. Transgenic plants are used to produce human hormones, clotting factors, enzymes and antibodies.
The amount by which individuals in a population differ from one another due to their genes, rather than their environment is called genetic variability. The study of genetic variability is part of population genetics. Genetic variability is caused by two factors: mutations and genetic recombination. The first of Bosselman’s biodiversity described “To what extent does lack of genetic variability itself threaten a species or population’s existence? How much should genetic variability be protected?”
Importance of Genetic Variability
Genetic variability has great importance for the Survival of species. Low genetic variability can put the survival of species in danger. For example, the Irish potato famine occurred due to low genetic variability for potatoes. Thus, single fungus destroyed all the same crops of potato.