India is playing a crucial role in development of neem
as pesticide in agriculture and pest control industry.
Neem in India is used for many purposes
Veterinary medicine
Unani medicine
Cosmetics
Malaria control
- public health
CROP PROTECTION AGENT
Nitrogen efficiency
Agro-forestry
Silviculture
Ayurvedic medicine
Ancient medicine
Agriculture
Modren medicine
Antifertility and other medical application
Genetical Variation
Taxonomical and Morphological Variation: Azadirachta A. Juss. of family Meliaceae,
sub-family Meliodeae, tribe Melieae has only two species: A indica A. Juss. is native to an
uncertain region of Indo-Southeastern Asian and A. excelsa (Jack) Jacobs (syn. A. integrifolia
Merr) is found in the Philippines, Sumatra, Malaya, Borneo, Aru and New Guinea.
In Thailand A. indica is reported by Lauridsen et al to have two varieties: A indica called
Sadao India and A. indica var. siamensis Valenton called Sadao Thai. The letter grows a wild
and is distributed widely throughout the country below 200m altitude within a well-defined
boundry towards west and north which extends to Cambodia and Laos in east and in south
stretches up to latitude 9 north. The two varieties of neem are identified on the basis of
Peroxidase isozyme patterns and pollen morphology. Moreover A. Indica var. indica has a
white flushing inflorescence and A. indica var. siamensis a red one. These two varieties
have been reported by Lauridsen et at to hybridize naturally in south near Prachuab Khiri
Khan on the peninsula giving rise to intermediate hybrid variates. In the north of this location
hybridization between varieties is interestingly absent because of a reproductive barrier
becoming functional between them due to difference in time of flowering.
An isolated natural provenance of A. indica from Doi Tao with no recent neem introductions
near it has been demarcated from Chirag Mai province of Thailand for seed collection.
Variation in Phenology. Normally neem is
evergreen because new leaves appear
before the old leaves are shed. In dry
localities of India the trees may shed all
leaves for a brief period and therefore,
appear to be deciduous. Timings and
duration of leaf shedding, flowering and seed
set are, therefore known to vary in different
geographic zones and provenances
especially in those of wet and very dry and in
those growing in widely separated regions.
No work has been done on pollination
mechanism and breeding systems of neem.
Chromosomal Races. The chromosome number for neem has been reported to be
2n=2810. Managenot and Styles and Vosa15 however report 2n=30 from root mitosis. The
possibility of existence of two or more chromosomal races in neem, therefore, needs to be
investigated.