Genetics and genetic engineering has placed an important role in improvement of plant production. There are following applications of genetics in plant improvement.
- Production of polyploid crops
I he techniques of genetics for ‘producing polyploid crops have improved the) Yield of crops. Today most of major crops like wheat, corn are poly ploid. Wheat is hexaploid. In 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 famine 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.
- Transgenic plants
The plants with foreign DNA are called transgenic plants. Many
New 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 world wide. The acreage is expected to triple in five years.
- 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. Vernolie 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 a channel proteins. These proteins transport Na and 11 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 ad 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 alt, drought and cold tolerant crops can increase the agricultural yields. It will reduce the need of more farm acreage ft will provide enough food for world population. The population is expected to become nearly double by 2050.
7. Increasing productivity
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 CO, So C4 cycle reduces the inefficiency of RuBP carboxylase.
(b) ‘Elie structure of stomata can he changed. It can increase carbon dioxide intake or cut down water loss.
(c) It can increase the efficiency of the enzyme RuBP earboxylase. kuBP captures C’0, in most plants.
8. Production 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.