Introduction to Plant Reproduction, Modes of Reproduction, Significance of Reproduction, Asexual Reproduction, Sexual Reproduction, Contributions of Scientists.

1. Notebook: Botany 3rd Sem
Created: 30-08-2020 07:59 Updated: 30-08-2020 10:22
Author: Ankit Srivastava
URL: https://en.wikipedia.org/wiki/Plant_reproduction
Unit 5 Introduction to Plant Reproduction
Modes of reproduction in plants: vegetative options - natural and artificial; introduction and Significance of
sexual reproduction. History (contributions of G.B. Amici, W. Hofmeister, E. Strasburger, S.G. Nawaschin, P.
Maheshwari, B.M. Johri, W.A. Jensen, J. Heslop-Harrison, and scope, Significance of Reproductive Biology
studies.
Defini on of Reproduc on in Plants
Plant reproduc on is the produc on of new offspring in plants, which can be accomplished by
sexual or asexual reproduc on. Sexual reproduc on produces offspring by the fusion of gametes,
resul ng in offspring gene cally different from the parent or parents. Asexual reproduc on
produces new individuals without the fusion of gametes, gene cally iden cal to the parent
plants and each other, except when muta ons occur.
Modes of Reproduc on in Plants
Plants reproduce by two methods.
The method in which fusion of gametes occurs is called sexual reproduc on and the mode of
reproduc on in which there occurs no fusion of gametes are called asexual reproduc on. These
methods are further classified into different types.
The offspring produced from asexual reproduc on is iden cal to its parent as there occurred no
fusion of gamete. Some mes the off springs varies when there occurs muta on.
In sexual reproduc on, there occurs forma on of seeds, which is by fer liza on of the embryos.
Apomixis is a kind of asexual reproduc on in which there occurs forma on of seeds but this seed
is not formed by fer liza on. The pollen contributes no gene c material here.
Vegeta ve Reproduc on

2. Types

3. Runners
Also known as stolons, runners are modified stems that, unlike rhizomes, grow from exis ng stems just
below the soil surface. As they are propagated, the buds on the modified stems produce roots and stems.
Those buds are more separated than the ones found on the rhizome.[19]
Examples of plants that use runners are strawberries and currants.
Bulbs
Bulbs are inflated parts of the stem within which lie the central shoots of new plants. They are
typically underground and are surrounded by plump and layered leaves that provide nutrients to
the new plant.[20]
Examples of plants that use bulbs are shallots, lilies and tulips.

4. Tubers
Tubers develop from either the stem or the root. Stem tubers grow from rhizomes or runners
that swell from storing nutrients while root tubers propagate from roots that are modified to
store nutrients and get too large and produce a new plant.[19]
Examples of stem tubers are potatoes and yams and examples of root tubers are sweet potatoes
and dahlias.
Suckers
Also known as root sprouts, suckers are plant stems that arise from buds on the base of parent
plants stems or on roots.[22]
Examples of plants that use suckers are apple, elm, and banana trees.

5. Introduc on and Significance of Sexual Reproduc on
30 August 2020
09:12
Sexual reproduc on involves two fundamental processes: meiosis, which rearranges the genes and
reduces the number of chromosomes, and fer liza on, 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 alterna on of genera ons, with two different mul cellularis
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).
The fusion of male and female gametes (fer liza on) produces a diploid zygote, which develops by mito c
cell divisions into a mul cellular sporophyte.
The mature sporophyte produces spores by meiosis, some mes referred to as "reduc on division"
because the chromosome pairs are separated once again to form single sets.
In mosses and liverworts, the gametophyte is rela vely large, and the sporophyte is a much smaller
structure that is never separated from the gametophyte. In ferns, gymnosperms, and flowering plants
(angiosperms), the gametophytes are rela vely small and the sporophyte is much larger. In gymnosperms
and flowering plants the megagametophyte is contained within the ovule (that may develop into a seed)
and the micro gametophyte is contained within a pollen grain. It is known as fer liza on.

6. Contribu ons of Major Scien sts
Giovanni Ba sta Amici
Wilhelm Hofmeister
Eduard Strasburger
Sergei Navashin

7. Brij Mohan Johri
Significance of Reproduc ve Biology
Knowledge on reproduc ve mechanisms of plants can help to assess the adap ve significance
and homology of descrip ve characters used in plant systema cs. Studying reproduc ve biology
can also give insight into the delimita on and classifica on of species and infraspecies
Plant reproduc ve biology is the study of the mechanisms and processes of sexual and asexual
reproduc on in plants. It may encompass the study of pollina on mechanisms, gene flow,
gene c varia on, and propagule dispersal between and within popula ons.