Agricultural Plants with Improved Traits | class 12 скачать в хорошем качестве

Agricultural Plants with Improved Traits | class 12

Aslam o alikum I am Hassam ur Rahman and I am teaching Fsc biology since 2014 .I am always trying to improve myself and provide best lecture to students.i am taking content for the lecture from authentic and relevant sources but human errors are possible . you are requested to please highlight the mistakes.My lectures are equally reliable for Fsc and mdcat students #visiblescience #mdcatbiology #alevelbiology #neetbiology # fsc biology This lecture is about Agricultural Plants with Improved Traits Cotton, com, potato and soybean plants have been engineered to be resistant to either insect predation or herbicides that are judged to be environmentally safe. Some com and cotton plants have been produced that are both insect and herbicide resistant. In 1999, transgenic crops were planted on more that 70 million acres world wide and the acreage is expected to triple in about ive years. If crops are resistant to a broad- spectrum herbicide and weeds are not then the herbicide can be used to kill the weeds. When herbicide resistant plants were planted weeds were easily controlled, less tillage was needed and soil erosion was minimized. One aim of genetic engineering is to produce crops that have the improved agricultural or food quality traits such as those listed in the table below: Improved Agricultural Traits Herbicide resistant Wheat, rice, sugar beets, canola Salt tolerant Cereals, rice, sugarcane Drought tolerant Cereals, rice, sugarcane Cold tolerant Cereals, rice, sugarcane Improved yield Cereals, rice, com, cotton Modiied wood pulp Trees Improved Food Quality Traits Fatty acid / oil content Com, soybeans Protein / starch content Cereals, potatoes, soybeans, rice, com Amino acid content Com, soybean Disease protected Wheat, com, potatoes Production of salt tolerant plants had been a dream of genetic engineer. Recently salt - tolerant Arabidopsis has been produced. For this the scientists irst identiied a gene coding for a channel protein that transports Na+ along with H+ across a vacuole membrane. Isolating Na+ in a vacuole prevents it from interfering with plant metabolism. Then, the scientists cloned the gene and used it to genetically engineer plants that overproduce the channel protein. The modiied plants thrived when watered with a salty solution. Irrigation, even into fresh water, inevitably leads to a salinization of soil that reduces crop yields. Today, crop production is limited by efects of salinization at about 50% of irrigated levels. The next step to solve this problem is to produce salt - tolerant crops. It is believed that the production not only of salt - but also drought and cold tolerant crops will reduce the need for added farm acreage by increasing agricultural yields that will provide enough food for a world population that is expected to nearly double by 2050. Some progress has also been made to increase the food quality of crops. Soybeans have been developed that mainly produce the monounsaturated fatty acid, oleic acid, a change that may improve human health. These altered plants also produce vernolic acid and ricinoleic acid, derivatives of oleic acid that can be used as hardenes in paints and plastics. The necessary genes were derived from Vemonia and castor bean seeds and were transferred into the soybean genomes. Genetic Engineering is also expected to increase productivity. To that end, stomata might be altered to boost carbon dioxide intake or cut down water loss. The eiciency of the enzyme RuBP carboxylase which captures C02 in plants could be improved. A team of Japanese scientists is working on introduc ing the C4 photosynthetic cycle into rice. Unlike C3 plants, C4 plants do well in hot dry weather. These modiications would require a more complete engineering of plant cells than the single gene transfers’ that have been done so far.