Question: 100% NCERT covered from Particular Keyword.Explanations are 100% from NCERT | [Difficult level: Easy] From NCERT NEET Derived Question.
Which one of the following shows maximum genetic diversity in India ?
1. Mango
2. Groundnut
3. Rice
4. Maize
Answer:(3)
Explanation :India has more than 50,000 genetic strains of Rice
Rice & Related points from NCERT
👉The genetic variation
shown by the medicinal plant Rauwolfia vomitoria growing in
different Himalayan ranges might be in terms of the potency and
concentration of the active chemical (reserpine) that the plant
produces.
👉India has more than 50,000 genetically different strains
of rice, and 1,000 varieties of mango.
👉Rice is an important food grain, the presence of which goes back
thousands of years in Asia’s agricultural history. There are an estimated
2,00,000 varieties of rice in India alone. The diversity of rice in India is
one of the richest in the world. Basmati rice is distinct for its unique
aroma and flavour and 27 documented varieties of Basmati are grown
in India. There is reference to Basmati in ancient texts, folklore and
poetry, as it has been grown for centuries
👉Western Ghats have a greater amphibian species diversity than
the Eastern Ghats.
👉The ‘bakanae’ (foolish seedling) disease of rice seedlings, was caused
by a fungal pathogen Gibberella fujikuroi. E. Kurosawa (1926) reported
the appearance of symptoms of the disease in rice seedlings when they
were treated with sterile filtrates of the fungus. The active substances
were later identified as gibberellic acid.
👉Ethylene
- Gaseous
- Senescence
- Ripening
- Horizontal seedling growth
- swelling axis
- Apical hook formation
- Enhance respiration= Respiratory climactic
- Break seed dormancy
- Break bud dormancy
- Germinate peanut seed
- sprouting potato tuber
- Internode elongation in deep water rice plant
- Root growth
- Root hair formation
- Increase absorption surface
- Initiate flowering in pineapple
- Synchronising fruit in pineapple
- Hasten fruit ripening in tomato and apple by etheophon
- Thinning of cheery wall nut and cotton
- Female flower in cucumber
👉Rice gamete chromosome number= 12
👉In some cereals such as rice and
wheat, pollen grains lose viability within 30 minutes of their release, and
in some members of Rosaceae, Leguminoseae and Solanaceae, they
maintain viability for months
👉endosperm is persistent in cereals – wheat, rice
and maize.
👉Endosperm may either be completely consumed by the
developing embryo (e.g., pea, groundnut, beans) before seed
maturation or it may persist in the mature seed (e.g. castor
and coconut) and be used up during seed germination
👉 Many non-human model
organisms, such as bacteria, yeast, Caenorhabditis elegans (a free living
non-pathogenic nematode), Drosophila (the fruit fly), plants (rice and
Arabidopsis), etc., have also been sequenced under Human Genome Project
👉The School of Cytogenetics and Radiation Research established at the
Indian Agricultural Research Institute (IARI) enabled Swaminathan and his
team to develop short-duration high-yielding varieties of rice including scented
Basmati.
👉Wheat and Rice: During the period 1960 to 2000, wheat production
increased from 11 million tonnes to 75 million tonnes while rice production
went up from 35 million tonnes to 89.5 million tonnes. This was due to the
development of semi-dwarf varieties of wheat and rice. Nobel laureate
Norman E. Borlaug, at International Centre for Wheat and Maize
Improvement in Mexico, developed semi-dwarf wheat. In 1963, several
varieties such as Sonalika and Kalyan Sona, which were high yielding and
disease resistant, were introduced all over the wheat-growing belt of India.
Semi-dwarf rice varieties were derived from IR-8, (developed at International
Rice Research Institute (IRRI), Philippines) and Taichung Native-1 (from
Taiwan). The derivatives were introduced in 1966. Later better-yielding semidwarf
varieties Jaya and Ratna were developed in India.
👉In 2000, maize hybrids that had twice the amount of the amino acids,
lysine and tryptophan, compared to existing maize hybrids were
developed.
👉Wheat variety, Atlas 66, having a high protein content, has
been used as a donor for improving cultivated wheat
👉It has been possible
to develop an iron-fortified rice variety containing over five times as much
iron as in commonly consumed varieties.
👉vitamin
A enriched carrots, spinach, pumpkin; vitamin C enriched bitter gourd,
bathua, mustard, tomato; iron and calcium enriched spinach and bathua;
and protein enriched beans – broad, lablab, French and garden peas.
👉enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’
enriched rice.
👉Bacillus thuringiensis (Bt for short). Bt toxin gene has
been cloned from the bacteria and been expressed in plants to provide
resistance to insects without the need for insecticides; in effect created a
bio-pesticide. Examples are Bt cotton, Bt corn, rice, tomato, potato and
soyabean etc.
