Candidates preparing for their CSIR NET exam might need to get some short study notes and strategies to apply while preparing for the key exam of their life. At this point, We at Byjus Exam Prep come up with short notes on Breeding in Animals & Plants, which comes under the Applied Biology section of the Life Science syllabus.
Our experienced subject-matter experts have meticulously designed this set of short notes to give you the most standard set of study materials to be focused upon. In this cut-throat competitive world, students need to prepare themselves with the best study materials to help them learn and for their future. So, here we are offering the best study notes that are reliable and can be used by the students during CSIR-NET 2021 preparation.
Study Notes on Breeding in Animals & Plants (Download PDF)
MARKER ASSISTED SELECTION
- The use of DNA markers to target the loci to assist phenotypic screening is known as Marker Assisted Selection (MAS).
- MAS helps to make selection decisions before phenotypes are available.
A broad terminology is: -
- Marker-Assisted Breeding (MAB) which includes apart from MAS.
- Several modern breeding strategies like marker-assisted recurrent selection (MARS).
- Marker-assisted Backcrossing (MABC)
- Genomic selection (GS).
- MAB (Marker-assisted breeding) is the application of molecular markers along with linkage maps and genomics to alter and improve plant or animal traits based on genotypic assays.
QTL
- An ideal marker is the one that allows inheritance to be followed across generations.
- Recent advances in molecular genetics offer methods to dissect the genetic variability of complex traits into Quantitative Trait Loci (QTL).
- Generally, a marker is associated to a QTL.
- The best scenario is when the marker and QTL are in same locus.
- For practical purposes the marker and QTL should be closely located so that recombination between marker and QTL is rare.
- Most traits of economic importance are complex quantitative traits controlled by many genes.
- QTL strictly applies to genes might have a large effect than the others and are called as major genes located at QTL.
- The pattern of inheritance of such genes may assist in selection.
BREEDING METHODS
1. INBREEDING
2. OUTBREEDING ⇒ CROSS BREEDING
3. HETEROSIS
- Mating of parents which are genetically related
- Pure line maintains the original characters.
- Inbreeding is when breeding is between offspring of same family as shown in diagram Aa breeds with Aa rabbit which are offspring of same family Aa and AA.
ADVANTAGES
- Increase homozygosity
- Production of pure lines
- Elimination of deleterious characters
- Production of valuable breeds
DISADVANTAGES
- Low yield
- Inbreeding depression
- Loss of heterozygous
- Less variation
OUTBREEDING
- Mating of unrelated individuals or not so closely related individuals.
- Crossbreeding occurs.
- Here breeding doesn’t occur within offspring of same family, here breeding occurs between members of different family. (As shown in diagram)
Result of outbreeding
- Heterogeneity or heterozygosity
- Variation
- High yield
- Produce more grains.
HETEROSIS
- Increased growth vigor or yield of hybrid over the parents called hybrid vigor.
- It brings superiority in F1 generation.
DOMINANCE HYPOTHESIS
- Hybrid vigor result from bringing together the maximum number of dominance favorable gene.
OVERDOMINANCE HYPOTHESIS
- Hybrid vigor due to superiority of heterozygous over the homozygous.
ANIMAL INBREEDING
- All Hybrids are INFERTILE.
EXAMPLES: -
- Female horse + male = MULE
- Female tiger + Male Lion = TIGON
- Female Lion + Male Tiger = LIGER (as shown below)
Marker-Assisted Selection
- Marker is a DNA Sequence.
- Serve as signal/flag host.
- Linked to gene of interest.
STEPS: -
→Download Study Notes on Breeding in Animals and Plants - CLICK HERE←
Enrol for CSIR NET 2021 Crash Courses - Join Online Classroom Program
Get Access to Unlimited Test Series for CSIR NET 2021 Exam
Check Out:
Complete Study Notes on Life Science - Download PDF
Most Expected Questions for the Upcoming CSIR NET Life Science 2021
Topic Wise Mind Maps for Life Science
BYJU'S Exam Prep
Download the BYJU’S Exam Prep App Now.
The Most Comprehensive Exam Prep App.
#DreamStriveSucceed
App Link: https://bit.ly/3sxBCsm
Comments
write a comment