IDEOTYPES (Model Plants)

IDEOTYPES (Model Plants)

    The concept of Ideotype was given by  Donald in 1968

Ideotype is the model plant which may be defined as " a biological model which is expected to perform or behave in a predictable manner within a defined environment".

On the basis of environment Donald and Hamblin (1976) identified two forms of Ideotypes i.e. 

isolation Ideotypes and competition Ideotypes

•IDEOTYPES FOR SOME CROPS:

WHEAT:

According to Donald (1968) the ideotype for wheat or the similar crop has following features :

a) To avoid lodging, there should be short strong stem

b) Few small erect leaves to allow the sunshine into its canopy

c) A large erect ear

d) The no. of fertile florets per unit area should be more so that HI is more 

e) There should be awns to increase the photosynthetic area

f) A single culm to avoid wasteful vegetative growth

h) Resistant to insect pests & diseases 

i) There must be proper partitioning and translocation of assimilates

MAIZE:

The plants have erect upper leaves and the lower leaves gradually become horizontal to allow the sunshine into its canopy

Proper movement of air into the field

The height of the plant is to be 1.5 metre in which 2-3 cobs may be produced on the nodes near the tassel

GRAM :

Pande and Suxena (1973) proposed the Ideotypes for  gram having following features :

a) The vegetative growth must be stopped before the starting of reproductive stage

b) The plant ia to have erect branching 

c) To harness the long photoperiod and favourable temperature at the time of flowering , there should be 2- 3 longer pods in the leaf axis and 2-3 seeds in each pod

ARHAR:

Pande   and Suxena suggested ideotypes having following features

1) The fast growth of plants canopy at least in the in the beginning

2) The reproductive phase starts after the closure of vegetative growth

3) Long floral axis having 2-3 flowers in each Trifoliate axis 

4) Synchronised flowering i.e. all the flowers come out at the same time 

5) Active root nodules for the long time 

6) Resistant to insect pests and Diseases

RAINFED UPLAND RICE:

a)Short growth duration

b) Effective deep root system

c) Dwarf plant having erect leaves and thick stem 

d) Early strong fertile tillering 

e) Synchronised flowering

f) Good number of panicles at higher density about 400 panicles per square metre

g) Highest number of grains per panicle 

h) Moderate seed dormancy 

I) Resistant to insect pests &diseases e 

g. Resistant to Helminthosporioum sp.

RAINFED WHEAT:

An ideotype of rainfed wheat was conceived and proposed by Dr.Asana 

1) Large no. Of spikletes 

2) Large peduncle 

3) Strong and deep root system

4) Flat leaves parallel to soil and

5) A grain development period coinciding with mean max.temp of 25°C

IDEOTYPES FOR DRYLAND FARMING:

a) Short growth duration

b) Effective root system

c) Drought tolerance

d) High yield potentially with altered morphology

✍️Agricos🌱🌾

Vaishnavi Nimkar

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