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Welcome: Three Methods of Plant Breeding

Wednesday, April 15, 2009

Three Methods of Plant Breeding

1) Open-pollination:

Open-pollinated or “standard” varieties of seeds breed true to their type. Seeds saved from such plants will produce a crop resembling their parents. While open-pollinated varieties may have originated from a genetic mutation, or a chance cross in the field, they have been stabilized and improved through years of selection by farmers and/or breeders choosing for desirable traits such as adaptability to climate and soil conditions, storage, disease and insect resistance, beauty, taste, ripening, and sugar content.

2) Hybridization:

Hybrids are the result of the deliberate crossing of two different parent varieties, usually inbreds. Typically, a corn variety will be crossed with a different corn variety and the result will always be a corn. Commercial growers look for “hybrid vigor” (synergistic effort which occurs when two diverse varieties are crossed), uniformity for mechanical harvesting and shipping, widespread adaptability to different climates and conditions, disease resistance, high yields, etc. Interspecific hybrids occur rarely in nature and genus boundaries are never crossed. Thus, it is not possible through sexual reproduction to cross a corn plant with a squash or a pig. Seed saved from hybrid plants is unstable. Traits from parents will segregate out in various combinations in the next generation. A fresh cross of the inbred seed lines will be required to maintain the variety.

3) Genetic Engineering:

Unlike open-pollination and hybridization, which occur in nature, genetic engineering requires human intervention in a laboratory setting directly manipulating DNA. Genetic engineers insert a foreign gene into the host DNA usually using one of two different methods: 1) ballistic — in which a gun injects foreign DNA, and 2) biological — in which a biological vector, usually a virus, carries the foreign gene into the DNA. Genetic engineering has the ability to cross all natural species boundaries and its products are often called “transgenic” (literally across genus boundaries). It is possible to insert a fish gene into a tomato or a pig gene into a corn — which would never occur in nature without human intervention.


At 9:40:00 AM , Anonymous Anonymous said...

سلام آقای صبوری
وبلاگ زیبا و پرمحتوایی دارید
تا به حال فرصت نکرده بودم بهتون سر بزنم.
امیدوارم که مشکلتون در رابطه با پروپوزال حل شده باشه .
موفق باشید
(ببخشید که انگلیسی ننوشتم آخه من زبانم خیلی فول نیست.)



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