Plant breeding Steps - Strategies for enhancement in food production, Biology, Class 12 Video Lecture

hello friends this video on food
production enhancement part 10 is
brought to you by exam feel calm no more
fear from exam so let us now look at the
factors which define improved plant
types so what are the characters which
tell us that this is a good plant diaper
this is an improved plant style so what
do we want what are the desirable
characteristics which we look for in any
plant type
first of all increased crop yield so we
want more and more crops to be produced
so the productivity should be very high
this is resistant plants now this is
resistance when we say that the plant
should have resistance against the
pathogens that is the disease-causing
microorganisms it should also have high
tolerance or resistance for the insect
pests so then they cannot spoil them
because a lot of plants get destroyed by
the pathogens or diseases and that is
why it is very important that improved
plant type should be disease resistant
increased tolerance to adverse
environmental conditions so what do we
mean by adverse environmental conditions
so when we say that we mean extreme
temperatures maybe if the temperature is
very high or the temperature is very low
the plants sometimes they are not able
to survive but if the plants have
increased tolerance to changes in
temperature then it is definitely an
improved variety again it should be able
to have increased tolerance for a
situation of drought that is when there
is no water or with salinity the salt
content in the water increases too much
or it decreases too much so in those
extreme conditions the plant should be
able to have high tolerance that means
it should be able to tolerate up to a
certain value so now we will look at the
steps for plant breeding how exactly
plant breeding is done so that is what
we will study here now the following
steps are carried out for breeding
plants
the first is palak
of variability so variations why do we
need variations or varieties because
when we want to look for the desirable
characteristics so in order to look for
desirable characteristics you need to
have a collection of all the possible
varieties of that plant so that you can
choose from that variety whichever is
the desired trait and whichever trade
you do not want for example you want to
go shopping so many go for shopping let
us suppose you want to buy a dress for
yourself now if the shop doesn't have a
variety of dresses then will you buy it
from there let us suppose the shop just
had the shopkeeper say is that he just
tells one dress so will you just look at
that one present but she is it no right
because you would like to see varieties
maybe you will go to some other shop
which hires some twenty to thirty
dresses of different types so that you
can look at all of them and then decide
which one you want so in a very similar
way you should collect all the varieties
of plants so that the desired treat can
be chosen from them now this is out the
first step for crossing a particular
crop that is this is like a prerequisite
now this collection of plants for a
particular crop is known as germ plasm
collection so this collection is termed
as germ plasm collection so this
collection will actually have all the
alleles for all the genes of a
particular crop so now the next step
would be evaluation and selection of
parents now out of from that germ plasm
collection you actually need to select
the desired traits for example in when
you go to buy your dress if the shop has
some twenty dresses you just need to
choose one out of there so in a very
similar way here also you have to look
at the entire collection and then you
have to select the parents parents means
the plants which you want to breathe so
you have to choose the male and the
female parkland which needs to be the
little bit
together so desired characters need to
be selected so if you take the example
of sugarcane the sugarcane example which
we took some time back the one which was
so Israel to see let us suppose this is
the first variety
this is variety number one business
variety number two so let us suppose
that the sugarcane well variety number
one has thin stem whereas the sugarcane
of variety number two has thick stem
again variety number one it has poor
sugar contained and variety number two
has good sugar container again variety
number one can grow in north whereas
variety number two can grow in salt so
now these are the various
characteristics of both variety number
one and two so now you have to select
the desired traits out of them so in a
very similar way here also when you have
collection of all the varieties you are
clay need to select the trades which you
want for example if you want it to grow
in north you want the stem you will
think and you want to have a good sugar
content so you will actually need to
select those please
so based on the traits which you want
you have to select that variety so here
we just have two varieties it is assumed
if we have a third variety which has
thin stem or sugar content and which is
which grows in South in that case we
will not select that variety tree we
will select a variety one and variety
two and then cross them with each other
so basically we are selecting the
parents in this step now once the
patterns are selected then what happens
cross-eyed realization among selected
plants now whichever parents we have
selected so breathing takes place that
is crossing will take place between
those two parents now house crossing
takes place the pollen grain of one plot
is placed on the stigma of the flowers
of the female plants that is how Paulo
that is all pollination and which in
turn is followed by fertilization takes
place in case of plants so once pollen
grain should come in contact with them
stigma of the other one
now once hybridization is taking place
what will happen output will be
produced that means the offsprings will
be produced now again the offsprings or
the outputs will have different traits
combination like as you have seen in
genetics like whenever a male and female
have crossed a lot of different types of
offsprings and produced so here also
different types of new plants will be
formed but now we have to select the
superior recombinant so whichever output
is obtained out of that we have to
select the desirable output and then
testing and reviews of new cultivars so
what happens later suppose the vegas
outputs which we get when we cross
variety one with variety to so let us
suppose the output one that we get has
thick stem for sugar can end and it is
it grows and soft so that is output one
now let us suppose the output to which
we get it has thin stem good sugar
content and it is good to grow in not
the third output now I mean that these
are the three outputs which are found I
am just trying to give you an example it
is suppose that in any output that is
suppose you have these three varieties
of output which are formed so it is
third variety of output which is form
this thick good sugar content and grows
and sound so now looking at these three
varieties we have to select the superior
where again which is the super variety
output to so this will be selected and
now testing will be done on put two so
this output two will be tested for its
quality will be tested to check if it is
disease resistance or not so it will be
tested for a few growing seasons now if
it is found to be suitable then it will
be commercialized so this phase is known
as testing and release so here it will
be tested that okay if this is the final
when you a variety which is of n so like
this be tested left
let's see if it is disease-resistant or
not or if it is able to survive well
under them to exact under that specific
climatic conditions or not so based on
that finally the new cultivars are
released or commercialized so this is
how I'm reading takes place thank you
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