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HAPLOID PLANTS. PRESENTED BY:-DEEPIKA. HAPLOID PLANTS. Haploids are the plants with a single set of (n) no. of chromosome in its cell. They have only the half set of chromosome. HISTORY.
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HAPLOID PLANTS PRESENTED BY:-DEEPIKA
HAPLOID PLANTS Haploids are the plants with a single set of (n) no. of chromosome in its cell. They have only the half set of chromosome.
HISTORY • Haploid plants from pollen grains were first produced byMAHESHWARIandGUHA in 1964 by culturing anthers of Datura. • The technique was further develop by J.P NITCH and C. NITCH. They showed that isolated microspore of TOBACCO produce complete plants.
HOW THE HAPLOID PLANTS ARE PRODUCED? • Haploid plants can be produced by anther culture or microspore culture. • When H.Vulgareare crossed with H.Bolbosum are selectively eliminated from developing embryos. Culture of 8-10 days old embryos enable the recovery of large no. of haploid seedling in both the cases.
Hordeumvulgare (2n=14;VV) Hordeumbulbosam (2n=14;BB) × Zygote (2n=14VB) Young embryo Haploid plant of H.vulgare Diploid plants of barley
PARAMETER FOR SUCCESSFUL ANTHER CULTURE • The donor plant. • The composition of nutrient media. • Physical factors.
PRODUCTION OF HOMOGYGOUS LINES FROM HAPLIOD PLANTS The chromosome number of haploid plant is readily doubled by using colchicines the plants so obtained are called DIPLOID PLANTS. Diploid plants are completely homozygous. Homozygous lines are produced during breeding of both self and cross pollinated crops time approach takes at least 6 yrs.
PARENT A Х PARENT B F1 HAPLOID PLANTS DIPLOID PLANTS SUPERIOR PROGENIES SUPERIOR
The haploid plants can be treated with colchicine to obtain doubled haploids
HAPLIOD AND DIPLOID CELL • When a cell divides by meiosis ,it ends up with only half amount of DNA it had before.That isHAPLOID CELL. • When two haploid join together to make one new cell with twice the amount of DNA ,That is DIPLOID CELL
ALTERNATION OF GENERATION • All the living creatures that use meiosis have to spend some time as haploid cell and some time as diploid cell. This is called alternation of generation. • Some creates spend most of their time as haploid cell and only become diploid for a short time before quickly going back to being haploid again.e.g Moss
VARIATION IN HAPLOID PLANTS • GAMETOCLONAL VARIATION:- Haploid plants regenerated from callus cultures show genetic variation i.e. gametoclonal variation. Such variation may be subjected to selection at haploid level, the chromosome no. of selected plant may be double to obtain homozygous plants.
ANALYTICAL BREEDING • Scheme involving extraction of dihaploids from tetraploid species, breeding level and then chromosome doubling of selected dihaploid lines to obtain tetraploid varieties.
DIPLOID BREEDING TECHNIQUE • A new technique hybrid rice varieties could boost the country rice production. For increase the country rice increase through faster development of hybrid rice varieties, agriculture science have reduced the time gap for breeding new rice varieties through the new method that is diploid breeding technique. • This short time required for breeding a new variety for 10-6 yrs.
ACHIEVEMENTS • Haploids have been effectively coupled with breeding programmes of crops like rice,wheat,tobacco barley,etc.resulted in the development of several varieties. • In Canada, two barley varieties, Mingo and Gwylan ,produced using the H. bulbosum route were superior to powdery mildew and barley yellow mosaic virus and other yield attributes.
Some varieties developed through haploid production HAPLOID PRO- CROP VARIETIES COUNTRY DUCTION ROUTE Anther culture Rice Tanfeng 1, XinXiu China Hua Yu 2,Ta Be 78 Anther culture Wheat Lung Hua 1, China Jing Hua1 Anther culture Tobacco Tan Yu1
APPLICATIONS • Production of homozygous DH lines using at least 4 yrs. • Haploid may be useful for isolation of mutants. • Diploid lines are useful tool for genome mapping. • Haploid plants of F hybrid with disease resistance can be screened to develop resistance variety
LIMITATIONS • In many crops, the application of this technique is not available since the technique for haploid production is not available. • In many crops its application is not feasible because large no. of haploid plants are not easily obtained.