Genetic divergence for yield and yield components and phenotyping against YMD in blackgram

Agriculture college, Bapatla
Department of Genetics and Plant Breeding
TOPIC: Genetic divergence for yield and yield components and
Phenotyping against YMD in Black gram (Vigna mungo)
SUBMITTED TO:
Dr. T. Srinivas sir,
Professor,
Head of the Department,
SUBMITTED BY:
K. Lakshmi Prasanna,
BAM-20-19,
M. Sc(Ag) 1st yr,
Department of GPBR
1
ACHARYA N.G. RANGAAGRICULTURAL UNIVERSITY,
AGRICULTURAL COLLEGE, BAPATLA
COURSE NO : GP-591
MASTER’S SEMINAR

CONTENTS
INTRODUCTION OF CROP
GENETIC DIVERGENCE
SYMPTOMS OF YMD
ABOUT CAUSAL ORGANISM
DISEASE MANAGEMENT
SCREENING METHODS
CASE STUDIES
2

• Kingdom : Plantae
• Division : spermatophyte
• Class : Dicotylydonae
• Order : Fabales
• Family : Fabaceae
• Genus : Vigna
• Species : mungo
SCIENTIFIC
CLASSIFICATION:
3

Black gram (Vigna mungo(L)Hepper)is commonly known as urd bean or minapa
pappu.
Self pollinated crop with outcrossing of 0.5%
Chromosome no -2n=22
Center of origin – South Asia
It is third most important pulse crops grown throught the India.
It is consumed in the form of ‘dal’( whole or split, husked or unhusked) or
perched.
It is used as nutritive fodder specially for milch animals.
INTRODUCTION
4

It is used as green manure crop as it fixes atmospheric nitrogen (42kg/ha/year) to
the soil through symbiosis and improves soil fertility.
High values of lysine makes black gram an excellent complement to rice in terms
of balanced nutrition.
It contains 24% proteins, 60% carbohydrates, 1.3% fat and is the richest source of
phosphoric acid among various pulses
5

Economic
importance
24%Protein
60% CHO,
1.3% Fat
Richest
source of
phosphoric
acid among
pulses
(5-6%)
Nutritive
fodder for
milch
cattle
As Green
manuring
crop
Binds soil
particles
& prevents
soil
erosion
Fixes
atm N2
(42kg/ha/yr)
to the soil
Blackgram
(Anirban and Amita, 2012) 6

• India currently represents the largest producer of black gram
accounting for more than 70% of global production. India is followed
by Myanmar and Pakistan.
India Andhra Pradesh
Area 56.02 Lakh ha 3.18 lakh ha
Production 30.60 lakh tonnes 3.10 lakh tonnes
Productivity 546 kg/ha 977 kg/ha
(Source: www. indiastat.com 2018-19)
7

It belongs to family Fabaceae or Leguminosae.
It is an erect, sub erect or trailing annual bushy plant.
It has branched tap root system with smooth, rounded root
nodules grows upto a height of 100cm.
Pods are narrow, cylindrical & 6 cm long with each pod
containing 4-10 black seeds.
Leaves are trifoliate, ovate with large petiole, stipules are
narrow.
Flowers are yellow in color and in clusters.
8

Leaves Pods Flower
9

An assessment of genetic diversity of pulses is an important first step in a program
to improve crop yield.
The sum total of genetic differences present among different individuals,
genotypes, strains, clones or populations of a species is called as Genetic
diversity.
Genetic diversity arises due to either geographical separation, crossability barriers
or due to different patterns of evolution.
It involves estimation of genetic similarity or dissimilarity between pairs of
entities & use of these estimates for grouping of entities.
10

Diversity of genotypes is important in selecting the parents for breeding
programes to yield superior transgressive segregants.
 Hence identification of diverse genotypes is important which can be done by
diversity analysis.
Diversity in plant genetic resources (PGR) provides opportunity for plant breeders
to develop new and improved cultivars with desirable characteristics, which
include both farmer-preferred traits (yield potential and large seed, etc.) and
breeders preferred traits (pest and disease resistance and photosensitivity, etc.).
11

ESTIMATION OF GENETIC DIVERGENCE:
MULTIVARIATE TECHNIQUES (MANOVA)
Metroglyph analysis ( Anderson)
 D 2 statistics (Mahalanobis)
 Cluster analysis
 Principal components analysis (PCA)
12

YELLOW MOSAIC DISEASE
13

SYMPTOMS
Initially mild scattered yellow spots appear on young leaves.
The next trifoliate leaves emerging from the growing apex show irregular yellow
& green patches alternating with each other.
Spots gradually increase in size & ultimately some leaves turn completely yellow.
Infected leaves also shows necrotic symptoms.
Diseased plants are stunted , mature late & produce very few flowers & pods.
Pods of infected plants are reduced in size & turn yellow in color.
14
(Manas kumar et al.,2014)

15
(Kothandaraman et al.,2016)

Initial appearance of green and
yellow patches on leaves
Complete yellowing of leaves at
final stage
16

About causal organism
YMD is caused by MYMV which is noticed more in urd bean & mung bean.
MYMV belongs to Geminiviridae and genera Begomovirus (Varasani et al., 2017;
Zerbini et al.,2017).
It has ss-DNA as its genome.
It is being transmitted by whiteflies (Bemisia tabaci) where it is delivered by its
proboscis into the phloem cells of the plants.
The viral aggregates appear in the host cell nuclei roughly two days before the
appearance of the symptoms.
The visible symptoms appear as scattered yellow-color spots on the young leaves
which later turn into yellow mosaic pattern resulting in yellowing, drying &
wilting of leaves.
17

The pods on the infected plant becomes smaller .
Thus photosynthetic efficiency will be reduced resulting in severe yield penalty.
Depending on age of the plant at which infection occurs, yield was reported from
85-100% (Singh et al.,2011).
The overall crop yield loss may range from 10 -100% depending on mungbean
genotype & stage of crop infection. (Singh,1980; Marimuthu et al.,1981; Bashir et
al.,2006).
18

In pulses, depending on viral nucleotide sequence identity, YMD is caused by four
distinct begmoviruses namely,
1. MYMV
2. MYMIV
3. Dolichos yellow mosaic virus(DoYMV)
4. Horsegram yellow mosaic virus(HgYMV)
MYMV is confined to southern India.
MYMIV is confined to Northern part of India
(Naimuddin et al.,2016)
19

Most commonly exploited measure is development & use of resistant varieties.
Thus effective screening for resistance towards YMV infection is a considerable
criterion in varietal development program of black gram (Vigna mungo (L.)
Hepper) varieties.
20

Cultural control:
Grow 7 rows of sorghum as border crop. (Raghupathi and Sabitha,
1994).
Yellow sticky traps attracts adult white flies. (Uthamasamy , 1989)
Foliar application of systemic insecticide (Dimethoate @750ml/ha) on 30
days after sowing.
 Treat seeds with Imidacloprid 70 WS @ 5ml/kg to control vector.
Rogue out MYMV infected plants early in the season to eliminate the
source of inoculum.
Grow resistant varieties to yellow mosaic.
Pant U 19, Pant U26 and Pant U 30
Disease Management
21

Phenotyping:
1. Natural field epiphytotic conditions
2. Artificial forced feeding method
3. Based on CI, PDI & AUDPC analysis
Genotyping (using molecular markers)
Methods of Screening for YMV
22

Screening for mung bean and urd bean under field conditions against MYMV is
done using INFECTOR ROW METHOD.
All the recommended cultural practices were followed except insecticide sprays
were not given.
Crop was monitored regularly & disease has its first appearance after 3rd of
planting.
Infection and disease severity of MYMV progressed in next 6 weeks.
Disease scoring was done 0-5 or 1-9 arbitrary scale.
The disease scoring was recorded from initial flowering to harvesting by weekly
intervals.
(Anirban and Amita, 2012)
1.Field screening
23

Modified MULLARP Scale (0-9)
24

25
(chandarjini devi et al.,2017)

Step 1:
Surface sterilized seeds kept for gemination in sterilized soilrite soil mix.
Step 2:
Acquisition Access Period (AAP)
Inoculation Access Period (IAP)
Step 3:
Phenotypic reaction to MYMIV was assessed after 7,14 & 21 days post infection.
(Anirban and Amita, 2012)
2. Artificial forced feeding method
26

Infector row method (Nene et al.,1972) was followed to ensure even distribution
of viral disease pressure throughout the experimental field using a suitable infector
line.
The response of the virus was assessed based on percent disease incidence and
disease severity.
Based on the disease severity, severity grades, designated with numerical values of
0-4, were developed and a scale of response value (0-1) corresponding to such
grades were denoted.
The coefficient of infection (CI) was calculated by multiplying the percent disease
incidence to the response value assigned for each severity grade following
standard methodology.
(Singh and Singh,2000)
3. Based on CI, PDI and AUPDC anlysis
27

Relative spread of the disease was calculated among the different accessions using
the Area Under Disease Progress Curve (AUPDC) following standard method
(Campbell and Madden,1990) as follows:
The disease incidence was recorded four times at 15 days intervals during the crop
growing season starting from 30 days after sowing (DAS) till pod formation stage
and these values were used to estimate the AUDPC.
28

CASE STUDY 1:
Name of journal : International Journal of current microbiology and applied sciences
NAAS Score : **
30

MATERIALS AND METHODS
Sixty four germplasm accessions were grown in rabi season 2017-18 at
Department of Agriculture Botany, College of Agriculture, Dapoli.
Each genotype was sown in a three rows of 2.4 meter length with a spacing of
30×20cm.
All accessions were raised in Randomized Block Design with three replications.
Observations were recorded from five randomly selected plants from each
genotype per replication for 13 characters.
A total of 64 germplasms were examined to study nature and magnitude of
genetic divergence using multivariate analysis through Mahalanobis D2 statistics.
31

 Genetic divergence analysis using D2 analysis grouped 64 black gram genotypes
into 9 distinct clusters.
32

Estimates of Intra and Inter cluster distances
33

Cluster mean of characters considered
34

Cluster mean values for traits considered
35

RESULTS AND DISCUSSIONS:
The analysis of variance showed high significant difference among genotypes for
6 out of 13 characters studied.
The cluster Ⅳ & Ⅴ emerged as largest with 16 genotypes and clusters Ⅵ, Ⅶ, Ⅷ
& Ⅸ are solitary.
Maximum intra cluster distance was found in cluster Ⅴ (D=9.108) and lowest was
found in cluster Ⅰ (D=5.865).
The inter cluster distance was found highest between cluster Ⅵ & Ⅷ (D=46.48)
followed by cluster Ⅵ & Ⅶ (D=37.06).
36

CONCLUSION
The above discussion showed that there is wide variation between the clusters.
Genotypes present in these clusters are suggested to provide a broad spectrum
variability in segregating generations & may be used as parents for future
hybridization programs to develop desirable genotypes.
37

CASE STUDY 2
Name of journal: Research journal of Agriculuture Sciences
NAAS Score : #*
Materials used:
 50 genotypes of black gram were raised at college farm, ANGRAU,
Hyderabad.
 Sown in randomized block design with 3 replications.
 Spacing is given as 30×10 cm.
38

Cluster composition based on D2 statistic
39

Estimates of Intra and Inter cluster distances
40

Cluster mean values for 8 clusters obtained by tocher method
41

Estimation of variability, heritability and genetic advance for
mean of yield components in balckgram
42

Results and discussions
On the basis of cluster D2 analysis, genotypes were grouped into 8 clusters.
Cluster Ⅰ is largest with 21 genotypes and clusters Ⅴ, Ⅵ, Ⅷ are monogenotypic.
The inter cluster distance was found highest between cluster Ⅶ & Ⅷ (403.21)
indicating greater divergence between them.
The minimum inter cluster distance was found between cluster Ⅰ & Ⅱ (42.77)
indicating these clusters were not genetically much diverse.
43

CONCLUSION
Here estimates of PCV are higher than estimates of GCV for all the traits under
study indicating environmental influence for these traits.
The association of high heritability with high genetic advance indicates additive
gene effects & could be improved through selection of these traits.
Low heritability with low genetic advance indicates non effective selection.
44

CASE STUDY 3:
Journal name : Journal of Plant pathology and microbiology
Forty nine varieties were evaluated R & D farm, ANGRAU, Guntur district.
Resistance screening was done during rabi 2015, in natural epidemic conditions
using alternative rows of highly susceptible varieties.
The disease was scored on a 1-9 arbitrary scale.
45

Grouping of genotypes screened against YMV in Black gram during Rabi,2015
46

Screening of black gram genotypes against YMV during rabi,2015
47

Results & Discussions:
This experiment revealed that 2 entries exhibited resistance (R) reaction rating
from 1.0-2.
6 genotypes exhibited moderate resistant (MR) reaction rating from 2.1-4.
3 were moderately susceptible (MS) with rating 4.1 -5.
2 were susceptible (S) with rating 5.1-7.
35 genotypes were highly susceptible (HS) with rating 7.1 -9.
48

Conclusion:
Evaluation of germplasm for disease resistance is crucial step in controlling plant
diseases through host plant resistance.
Genes conferring resistance can be to a certain extant identified through routine
screening procedures such as germplasm evaluation.
In the case of YMV in blackgram , of 49 genotypes screened, 2 entries have been
identified exhibiting promising reaction to YMV resistance.
Identification of resistant lines is essential in the ambit of integrated disease
management which is upcoming concept in the field of agriculture.
 Here genotypes LBG-17, LBG-402, LBG-645, LBG-685 are highly susceptible to
YMV but agronomical & quality wise were superior.
Hence improvement of these varieties for YMV resistance it taken.
49

Case Study 4:
Name of journal : Theoretical and applied genetics
NAAS Score : 10.44
50

Materials and methods:
Two resistant lines of black gram UPU-2 & Pant U-84 and a
susceptible line UL-2 were used as parents for study.
Both of these resistant varieties were spreading types with ovate leaf
and black seed.
Susceptible one is having hastate leaf with green seed and erect palnt
type.
51

F1 crosses:
UPU-2 ×UL-2
UL-2×Pant-U-84
Pant-U-84× UL-2
Back crosses:
(UL-2×Pant-U-84) ×UL-2
 (UL-2 ×Pant-U-84) ×Pant-U-84
Pant-U-84 ×(UL-2 ×Pant-U-84)
52

The row length was 5m.
Row to row and plant to plant spacing is 50 and 10 cm, respectively.
UL-2 , the highly susceptible parent was replicated after every 5 rows to intensify
inoculum from natural sources.
Disease severity was scored on 1-9 scale.
53

Results and discussion
In all where three F1’s involved UL-2 as susceptible parent & Pant U-84 and
UPU-2 as resistant parents, susceptibility was dominant over recessive.
The UL-2 Pant U-84 and its reciprocal cross showed same degree of susceptibility
indicating the involvement of only nuclear genes.
The F2 populations from all 3 crosses showed a ratio of 1:15
Back crosses involving a susceptible parent showed susceptible reaction for all the
plants while involving with a resistant parent segregated in 1R:3S ratios,
indicating two recessive genes were responsible for resistance in resistant varities.
54

Segregation for resistance to YMV in F2 and back cross programmes
55

Reaction of parents and F1 to YMV
56

CONCLUSION
Since two recessive genes are involved in resistant donors of black gram it is
suggested that in a resistance breeding programmes large populations of
segregating generations should be grown to recover enough resistant lines.
57

58

Genetic divergence for yield and yield components and phenotyping against YMD in blackgram

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