🌻 Botany of Oilseed Crops

This lesson covers core principles and exam-focused points from this topic in plant breeding.

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Castor _ Ricinus communis _ (2n=20) Euphorbiaceae

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Botany

Habit varies, mostly herbs but shrubs and trees are also common. Leaves simple or

compound stipulate, latex commonly present, inflorescence in its ultimate arrangements is

cymose, flowers small, regular, unisexual, perianth usually calycine, rarely petaloid sometimes

altogether wanting, male flower –stamens a many as double as many as perianth leaves or

numerous of flower or sometimes only one, the male flowers sometimes rudiment of the ovary,

female flower ovary generally three celled, ovules one or two in each chamber, styles and

stigmas as many as the cells, fruit (rigma) generally a capsule splitting into three coccid that

separate from a persistent central column

Distinguishing characters .

Presence of bloom –Ashy coating on the leaves and stem of the plant. Monoecious

condition- unisexual flowers, male at the bottom and female at the top. Androecium –

polyadelphous condition, filaments branched. The hilum almost concealed under the carancle.

Presence of thin leaf like cotyledon. Toxic alkaloids like ricin (blood coagulant) ricinin and

allergen are present.

Fruits (Regma )

It develops from tricarpellary syncarpous superior trilocular ovary and splilts into many

parts called cocci. Four distinct size groups of fruits namely 1)very small fruits are found in

ornamental types and in some of the wild perennial types. 2) Small and 3) medium types are

preferred for cultivation since they fairly high oil content varying from 45 to 57 %. 4) Big seeds

have generally low oil content of less than 40%. Very small seeds are preferred for medicinal

purposes.

On the fruit the epicarp may be either smooth or warty or spiny. Attractively colored

types of horticultural value with colored inflorescences and fruits have been evolved. The seeds

color ranges from white to gray deep chocolate, purple and red. Mottling is also much varying.

The seed has no dormancy.

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Sunflower - _ Helianthus annus _ (2n= 34) Asteraceae

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Botany

Plants are usually herbs, leaves exstipulate,flowers aggregated into heads, an involucre

of bracts surrounds the head or capitulum, calyx reduced to bristles or modified into papas,

corolla (5) valvate in all disc florets, but in marginal ray florets which may sterile or lack

stamens and acts as an attraction for insects, inner hermaphrodite bisexual flowers . Stamens

epipetalous with syngenesious anthers forming a ring through which the style passes. Stigmas 2.

Ovary inferior, one chambered with one anatropous ovule, fruit-achene (A small hard dry

indenescent one seeded fruit. The wall of single seed is free from the hard pericarp or wall of the

fruit)

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Safflower _ Carthamus tinctorius ( _ 2n = 24) Asteraceae

Safflower is an important oilseed crop in India. It is slowly becoming of increasing

importance as an oil crop for the drier parts of tropics and subtropic. In India it is cultivated for

both oil and reddish dye called safflower dye (cathamin) from florets. At the time of full bloom

flowers collected and corolla alones removed and dried. Yellow dye is obtained by washing and

dissolving it is water. There are two coloring matters. 1. Yellow pigment soluble in water and red

color soluble in alkalis. The seed /fruit is achene

Rape and Mustard Brassica sp. (2n=16, 18, 20, 22, 36)

Botany of cruciferae.

Annual, biennial or perennial herbs, a watery sap present, plants emit a sulphorous odour.

Stem covered by unicellular stellate hairs. Flowers arranged in typical racemes, usually

ebractate, sepals in two alternating dimerous whorls, petals 4, clawed diagonally placed stamens

tetra dynamous carpels 2, ovary two chambered, the development of a false septum,ovules

numerous on two parietal placentas. Fruit a Siliqua (It develops from bicarpellary syncarpous

gynoecium with parietal placentation and a false septum. It is a long narrow multiseeded fruit

which dehisces from below upwards by both sutures. Siliqula. It is a broad flat and shortened

form of siliqua.)

The group rape and mustard includes the oil yielding species of Brassica. The

commercial Indian rape seed and mustard are often mixture of rape seed, mustard and colza in

varying proportion. The seeds go by different name in different parts of the country. Generally

both colza (sarson) and rape (toria) are called together rape seed. Rai is mustard. Cultivated

Brassica can be broadly divided into two distinct types.

1. Vegetable type - cabbage,( Brassica oleraceae - var capitata.) cauliflower ( Brassica

oleraceae varbotrytis). Turnip ( Brassica oleraceae var rapa)

2. Oil seed type . 1) Rape seed Brassica compestris and 2 ) Mustard Brassica nigra .

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Rape seed

a) Brassica compestris (2n= 20)

Indian rape seed is self sterile in natures. Important oilseed crop of N.India. There are three

cultivated types.

Brassica compestris var. brown sarson

Brassica compestris var. Yellow sarson

Brassica compestris var. toria

b) Brassica napus 2n=38 European rape seed. Self fertile grown in Europe

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Mustard

a) B. nigra (2n=16) Black or true mustard. Banarasi rai contains 28% of fixed

oil used as medicine . Oil is pungent due to presence of glucoside sinigrin mostly used as

contiments.

b) B. alla 2n=24. White mustard or ujli sarson. Young seedlings used as salads. Seeds yellowish

in color contains 30% oil.

c) B. juncea 2n=36 Indian mustard.(Brown sarson).Popularly known as rai contains 35% oil.

Leaves are used as herbal medicines. Most pungent among cultivated oil seeds. It contains

glucoside sinigrin.

The oil producing species of Brasicca are all cross fertilized.

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Key characters

Leaves two types 1) stem leaves bigger, lance shaped and serrated. Flower leaf small

smooth margin. Androecium tetradynamous . Fruit sliqua. The oil content of the seed varies

from 30-45% depending on the variety.

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Fibers

The fibers are obtained from the sclerenchymatous cells found in the plant body and these

fiber cells occur either in groups or bundles. Chemically the fiber cell consists chiefly of

cellulose with lignin or semi cellulose or any other substances. The commercial term fiber

includes generally all thin and slender substances, which can be spun or made use of as fine

stuffing material. Fiber cells are non-living structures, when mature and serve as a purely

mechanical function, i.e. they impart strength and rigidity to the plant body.

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Summary Cheat Sheet

Quick Recall Points

• This lesson focuses on key plant breeding concepts, terminology, and exam-relevant applications.
• Review major definitions, classifications, and method-wise distinctions from the sections above.
• Revise tables and examples from this lesson for fast pre-exam recall.

Exam Traps

• Do not confuse similarly named breeding methods without checking their core selection logic.
• Pay attention to crop-specific examples because the same principle can behave differently by species.

References

1 source • [1]

[1]

Standard Plant Breeding Class Notes (GPBR211)

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