You are a botanist working in the area of plant breeding. Describe the various steps that you will u
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Answer:
Explanation:
Plant breeding is the purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation, give better yields and are disease resistant. Classical plant breeding involves crossing or hybridization of pure lines, followed by artificial selection to produce plants with desirable traits of higher yield, nutrition and resistance to diseases.
Plant breeding programmes are carried out in a systematic way. The main steps in breeding a new genetic variety of a crop are :
a. Collection of variability
b. Evaluation and selection of parents
c. Cross hybridisation among the selected parents
d. Selection and testing of superior recombinants
e. Testing, release and commercialization of new cultivars.
a. Collection of variability :
Genetic variability is the root of any breeding programme. In many crops pre- existing genetic variability is available from wild relatives of the crop. Collection and preservation of all the different wild varieties, species and relatives of the cultivated species and evaluating them for their characteristics is a pre-requisite for effective exploitation of natural genes available in the populations. The entire collection having all the diverse alleles for all genes in a given crop is called germplasm collection.
b. Evaluation and selection of parents :
The germplasm is evaluated so as to identify plants with desirable combination of characters. The selected plants are multiplied and used in the process of hybridisation. Purelines are created wherever desirable and possible.
c. Cross hybridisation among the selected parents :
The desired characters have very often to be combined from two different plants -parents, for example high protein quality of one parent may need to be combined with disease resistance from another parent. This is possible by cross hybridizing the two parents to produce hybrids that genetically combine the desired characters in one plant. This is a very time-consuming and tedious process since the pollen grains from the desirable plant chosen as male parent have to be collected and placed on the stigma of the flowers selected as female parent. Also, it is not necessary that the hybrids do combine the desirable characters; usually only one in few hundred to a thousand crosses shows the desirable combination.
d. Selection and testing of superior recombinants :
This step consists of selecting, among the progeny of the hybrids, those plants that have the desired character combination. The selection process is crucial to the success of the breeding objective and requires careful scientific evaluation of the progeny. This step yields plants that are superior to both of the parents .Very often more than one superior progeny plant may become available. These are self-pollinated for several generations till they reach a state of uniformity –homozygosity, so that the characters will not segregate in the progeny.
e. Testing, release and commercialisation of new cultivars :
The newly selected lines are evaluated for their yield and other agronomic traits of quality, disease resistance, etc. This evaluation is done by growing these in the research fields and recording their performance under ideal fertilizer application, irrigation, and other crop management practices. The evaluation in research fields is followed by testing the materials in farmers’ fields, for at least three growing seasons at several locations in the country, representing all the agro climatic zones where the crop is usually grown. The material is evaluated in comparison to the best available local crop cultivar – a check or reference cultivar. After evaluation the variety can be released for the farmers.
Answer:
At the point when the botanist is working in the field of rearing plants and building up another assortment, there are sure advances which are followed. The new plant assortment can be created by utilizing various strategies. A portion of the basic procedures are depicted as follows:
(1) Protoplast combination: The strategy is otherwise called substantial hybridisation. The protoplasts of the cells of two distinct plants are utilized. the protoplast is melded utilizing various synthetic concoctions like PEG. This outcomes in the development of a cell with both the characters. The cell can be refined to build up the plant.
(2) Emasculation and packing: The plants which are chosen are utilized for the procedure of cross fertilization. This is a piece of the hybridisation method. The anthers are expelled from the promiscuous blossom which is known as weakening to forestall self fertilization. The blossoms are sacked to keep fertilization from some other sources. The blossom is cleaned with dusts of the chose male plant and cross fertilization is accomplished. This outcomes in the advancement of an assortment with the characters of plants which are hereditarily unique.
(3) Hybidisation: Different strategies like joining can be utilized to build up another assortment. The two plants of alluring characters are chosen and utilized for uniting. This outcomes being developed of plant with new arrangement of characters.