This document provides an overview of plant classification systems based on pollination and reproduction. It discusses self-pollinated, cross-pollinated, and often cross-pollinated crops. It also discusses classification of plants as either seed propagated (sexual reproduction) or vegetatively propagated (asexual reproduction). Key terms discussed include pollination, open pollinated plants, self-pollination, cross-pollination, and modes of vegetative and sexual plant reproduction.

1. CLASSIFICATION OF
PLANTS
Summited to: Dr. Kaushik Panigrah
Submitted by: Rashmi Rekha Jena
(02HO/16)

2. Introduction
 Classification is a general process related to categorization, the process in which ideas
and objects are recognized, differentiated, and understood.
 A classification system is an approach to accomplishing classification.
 In plant breeding crops can be broadly classified on the basis of pollination and
reproduction.
 Plants based on mode of pollination:- a) Self pollinated crop
b) Cross pollinated crop
c) Often cross pollinated crop
 Plants based on mode of reproduction:- a) Seed propagated crop(sexual)
b) Vegetatively propagated crop(asexual)

3. Pollination?
 Pollination: The transfer of pollen from the male
anther to the female stigma.
 Plants are stationary (usually) and thus depend
on external forces to bring their gametes
together.
 As a result, plant sex is extraordinarily varied
and competitive.
 Some plants species may be specialized for one
pollinator.
 Some plants may be served by a wide range of
pollinators. Such plant species are called
generalists.

4. Open pollinated plants
 "Open pollinated" generally refers to seeds that will "breed
true." When the plants of an open-pollinated variety self-
pollinate, or are pollinated by another representative of the
same variety, the resulting seeds will produce plants roughly
identical to their parents.
 This is in contrast to the seeds produced by plants that are
the result of a recent cross (such as, but not confined to, an
F1 hybrid), which are likely to show a wide variety of
differing characteristics
 Open-pollinated varieties are also often referred to as
standard varieties or, when the seeds have been saved across
generations or across several decades, heirloom varieties.
While heirlooms are usually open-pollinated, open-
pollinated seeds are not necessarily heirlooms; open-
pollinated varieties are still being developed.

5.  One of the challenges in maintaining an open-pollinated variety is avoiding
introduction of pollen from other strains. Based on how broadly the pollen for the
plant tends to disperse, it can be controlled to varying degrees by greenhouses, tall
wall enclosures, field isolation, or other techniques.
 Because they breed true, the seeds of open-pollinated plants are often saved by home
gardeners and farmers
 the term "open pollination" refers to pollination by insects, birds, wind, or other
natural mechanisms. This can be contrasted with cleistogamy, closed pollination,
which is one of the many types of self pollination. When used in this sense, open
pollination may contrast with controlled pollination, a procedure used to ensure that
all seeds of a crop are descended from parents with known traits, and are therefore
more likely to have the desired traits.
 The seeds of open-pollinated plants will produce new generations of those plants;
however, because breeding is uncontrolled and the pollen (male parent) source is
unknown, open pollination may result in plants that vary widely in genetic traits.
Open pollination may increase biodiversity.

6. Self-pollinated crop
 Self-pollination is when pollen from the same plant arrives at the stigma
of a flower (in flowering plants) or at the ovule (in Gymnosperms).
 There are two types of self-pollination: In autogamy, pollen is transferred
to the stigma of the same flower.
 In geitonogamy, pollen is transferred from the anther of one flower to
the stigma of another flower on the same flowering plant, or from
microsporangium to ovule within a single (monoecious) Gymnosperm.
 Some plants have mechanisms that ensure autogamy, such as flowers that
do not open (cleistogamy), or stamens that move to come into contact
with the stigma. The term selfing that is often used as a synonym, is not
limited to self-pollination, but also applies to other types of (self
fertilizations)
 Eg:-Rice, Wheat, Barley, Oats, Chickpea, Pea, Cowpea, Lentil, Green gram,
Black gram, Soybean, Common bean, Moth bean, Linseed, Sesame,
Khesari, Sunhemp, Chillies, Brinjal, Tomato, Okra, Peanut, Potato, etc.

8. Cross pollinated crops
 Cross pollination is one way in which plants reproduce.
 There are many advantages to this method, the foremost is introducing genetic diversity to the
plant, which keeps is resistant to disease.
 Some plants, such as willows, have to be cross-pollinated because the male and female flowers
are not on the same plants.
 In tropical regions, cross pollination occurs via hummingbird, rodents, bats and even lemurs.
Occasionally snails act as cross pollinators. Some plants are pollinated by water and wind.
 Eg:- Corn, Pearlmillet, Rye, Alfalfa, Radish, Cabbage, Sunflower, Sugarbeet, Castor, Red clover,
White clover, Safflower, Spinach, Onion, Garlic, Turnip, Squash, Muskmelon, Watermelon,
Cucumber, Pumpkin, Kenaf, Oilpalm, Carrot, Coconut, Papaya, Sugarcane, Coffee, Cocoa, Tea,
Apple, Pears, Peaches, Cherries, grapes, Almond Strawberries, Pine apple, Banana, Cashew, Irish,
Cassava, Taro, Rubber, etc.

10. Pollination by different agent in cross pollinated crops

12. Often Cross Pollinated Crops
 In many self pollinating species, cross pollination may occur up to 5% or even reach to 30%, such
species are referred as often cross pollinating species.
 Example:-
 Sorghum
 Triticale
 Pigeonpea
 Tobacco Jowar
 Cotton
 Broad Bean
 Jute
 Rai
 Brassica compestris var.yellow Sarson (yellow Sarson)
 B.compestris var. Toria.

16. Plant reproduction
 Plant reproduction is the production of new individuals or offspring in plants, which can
be accomplished by sexual or asexual(vegetative) reproduction.
 Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring
genetically different from the parent or parents.
 Asexual reproduction produces new individuals without the fusion of gametes, genetically
identical to the parent plants and each other, except when mutations occur.
 In seed plants, the offspring can be packaged in a protective seed, which is used as an
agent of dispersal.

17. Vegetative propagated plants
 Plants have two main types of asexual reproduction in which new plants are
produced that are genetically identical clones of the parent individual.
 Vegetative reproduction involves a vegetative piece of the original plant (budding,
tillering, etc.) and is distinguished from apomixis, which is a replacement for sexual
reproduction, and in some cases involves seeds.
 Apomixis occurs in many plant species and also in some non-plant organisms.
 For apomixis and similar processes in non-plant organisms, see parthenogenesis.

18. Apomixis
 Seeds generated by apomixis are a means of asexual reproduction, involving the
formation and dispersal of seeds that do not originate from the fertilization of the
embryos.
 Hawkweed (Hieracium), dandelion (Taraxacum), some Citrus (Citrus) and Kentucky
blue grass (Poa pratensis) all use this form of asexual reproduction.
 Pseudogamy occurs in some plants that have apomictic seeds, where pollination is
often needed to initiate embryo growth, though the pollen contributes no genetic
material to the developing offspring.
 Other forms of apomixis occur in plants also, including the generation of a plantlet
in replacement of a seed or the generation of bulbils instead of flowers, where new
cloned individuals are produced.

19. Seed propagated plant
 Sexual reproduction involves two fundamental processes: meiosis, which rearranges the genes and
reduces the number of chromosomes, and fertilization, which restores the chromosome to a complete
diploid number.
 In between these two processes, different types of plants and algae vary, but many of them, including
all land plants, undergo alternation of generations, with two different multicellular structures (phases),
a gametophyte and a sporophyte.
 The evolutionary origin and adaptive significance of sexual reproduction are discussed in the pages
“Evolution of sexual reproduction” and “Origin and function of meiosis.”
 The gametophyte is the multicellular structure (plant) that is haploid, containing a single set of
chromosomes in each cell.The gametophyte produces male or female gametes (or both), by a process of
cell division called mitosis.
 In vascular plants with separate gametophytes, female gametophytes are known as mega gametophytes
(mega=large, they produce the large egg cells) and the male gametophytes are called micro
gametophytes (micro=small, they produce the small sperm cells).