PRESENTATION ON SORGHUM FLORAL

BIOLOGY

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INTRODUCTION

Common name: jowar, jola, jonna,

Scientific name :Sorghum bicolor L. Monech

Chromosome number: 2n=2x=20

Origin :Ethiopia

Progenitor : S. arundinaceum (2n=2x=20)

S. sudanese (2n=2x=20)

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TAXONOMY

Kingdom : plantae

Family : Poaceae

Genus : Sorghum

Species : bicolor

Other related species : guinea, caudatum, kafir,

durra.

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FEATURE OF SORGHUM CROPIT IS C-4 PLANT.

IT IS GROWN EXTENSIVELY IN TROPICAL AND

SUBTROPICAL ENVIRONMENT

MORE SUITABLE FOR RAIN FED FARMING

FIFTH POSITION AT WORLD LEVEL BOTH IN

AREA AND PRODUCTION AFTER WHEAT,

MAIZE, RICE , BARLEY.

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BOTANY

Sorghum is a annual or perennial grass.

Root : fibrous and extensively developed, either non rhizomatous or weakly rhizomatous well developed rhizome are found in Johnson grass (S. halepense).

Stem : erect, made up of a series of alternative nodes and internodes.

Pith may be sweet or insipid, juicy or dry.

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contd….

Leaves :are arranged on stem in two rank alternating on opposite side.

Number of leaves varies from 7-28.

Panicle : varies from lose to compact .

The panicle has a central axis divides into nodes and internodes

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FLOWER STRUCTURE

Inflorescence of the sorghum varies from compact head to open

panicle.

Spikelet occur in pair (one large sessile and small

pedicelled) except for the terminal spikelet.

Flowers called a florets & they are enclosed by two bracts called the

Palea and Lemma (Lower Bract).

The Lemma encloses the Palea and the Flower Organs.

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contd……

Florets occur in groups called Spikelet.

Each spikelet is subtended by bracts called Glumes.

The Perianth of each floret is represented by two transparent scales

called Lodicules.

There are generally 3 stamens and Gynoecium with two hairy

stigmatic lobes. The Stigmatic trichomes are designed to capture

wind-borne Pollen

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FLORAL BIOLOGY

sorghum inflorescence blooms in early morning in

basipetal manner

the anther and stigma push out as the glumes open.

Stigma are receptive from 1-2 days before

blooming to 8-16 days after blooming depending

on the variety and the climatic condition

Stigma before the anther dehiscence are

subjected cross pollination (<5 to 50%)

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contd….

Cross pollination is greater in variety with open panicle than in

compact panicle varieties.

Anthessis begins from 2 a.m. and opening continues till 8 a.m. and

may prolong to 10 a.m.

Fertilization takes 1 to 2 hours after pollination

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SELFING

bagging

Isolation

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CROSSING TECHNIQUE

Important crossing tools

Hand emasculation:

Emasculation by hot water treatment

Use of male sterile line

Plastic bag/mass emasculation techniques

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POLLINATION

Pollens are collected in paper for few hours after

dehiscence and collected pollens are uniformly

spread on the emasculated panicle

Fertilization takes place 2 hours after pollination

Embryo is formed 12 days after fertilization

Development of embryo and endosperm

continues along with starch accumulation for

about 30 days

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