Genentic Divergence among Local Maize (Zea mays L.) Cultivars of Kashmir Valley.
F.A. Nehvi, M.I. Makhdoomi, Vaseem Yousuf, Fayaz Ahmed
Bahar , Sabeena Naseer and Z.A Dar
K.D. Research Station
S K University of Agricultural Sciences &
Technology of Kashmir
ABSTRACT
Variability
studies in local maize cultivars revealed high genotypic coefficient of
variation coupled with high heritability and genetic advance for grain yield
and ear height. Genetic divergence among 50 local maize cultivars was studied
through multivariate analysis following D2
statistics. Cultivars were grouped into eight distinct clusters. Intra and
inter cluster distances among the groups were determined and analyzed with
respect to cluster means. Maximum intercluster distance was recorded between
cluster 6 and cluster 7. cluster mean analysis indicated that the clusters
containing solitary cultivars mostly differed for all the traits expecting for
ear length. Ear length followed by grain yield contributed maximum to the
divergence. Tremendous potential exists for introgression of allelic resources present
in these adopted local cultivars into existing potential high yielding
composites for recovery of high yielding in recombinants.
Key
Words : Variability, Divergence, Maize
(Zea mays L.)
INTRODUCTION
In crop improvement genetic diversity has been considered
as important factor which is an essential prerequisite for hybridization
programme for obtaining high yielding progenies. Maize breeders are
consistently emphasizing the importance of diversity among parental genotypes
as a significant factor contributing to heterotic hybrids (Ahloowalia and
Dhawan, 1963; Hallauer, 1972). Quantitative measurement of genetic divergence
among individuals have enabled plant breeders to understand the social
affinities and evolutionary pattern in various species of cultivated plants as
well as in making decisions for the selection of best parental combinations in
hybridization programme (Morishima and Oka 1960; Rao, 1958). The usefulness of
multivariate analysis, for the study of morphologically complex individuals and
for measuring the degree of divergence between biological populations has been
shown in different fields of research (Blackith and Reyment, 1971; Hussaini et
al., 1977). Cluster analysis is commonly
used for studying the genetic diversity and for forming core subjects for
grouping accessions with similar characteristics into homogeneous categories.
Among several methods of multivariate analysis, Mahalanobis D2
statistics has been shown to be very useful in selecting parents for
hybridization that meet the objectives of plant breeder. Generally large number
of quantitative traits is available for such multivariate analysis.
Jammu
and Kashmir state is a source of biological heritage and 90% of the maize area
in the state is under the cultivation of local cultivars with distinct
morphological difference for plant type, grain shape and grain colour. These
cultivars have adoptability on account of early maturity and resistance to
biotic and abiotic stresses. The present investigation was therefore undertaken
to study the extent of variability and identify divergent lines for their
future use in breeding programme.
MATERIALS AND METHODS
The experimental material comprised of 50 local maize
cultivars collected from maize growing areas of Kashmir valley and 4 high
yielding maize composites viz C8, C15, C6 and
super-l used as checks. 50 cob samples were collected from villages of Khag,
Yusmarg, Neilnag, Dalwash, Kralpathri (District Budgam); Shopian, Balpora,
Malanpora, Tral, Turkwangwam (District Pulwama); Uri, Gurez, Bandipora, Pattan,
Wagoora, Tangmarg, Farozpura (District Baramula); Qazigund, Dooru, Verinag,
Kulgam, Pombai, Pahalgam, Mattan, Kokernag (District Anantnag).Kangan Wangat,
Satrain, and Babanagri, Sonmarg, Dara (District Srinagar). 25 sampled village
shows preference for different grain colours viz; orange yellow, yellow,
creamish, white and purple. Progeny rows from each sampled cob were planted at
K D Research Station. Each plot
comprised of 2 rows of 5m length. All recommended agronomic practices were
followed to raise an ideal crop. Data on 5 competitive plants from each plot
was recorded on 7 maturity, morphological and yield related traits viz; days to
50% silking, days to 50% anthesis, days to husk browning, ear height (cm), ear
length (cm) and grain yield (kg/ha). Data was subjected to analysis of variance
and coffecient of variability, heritability and genetic advance was estimated
as per the methods of Johson et al.
(1955). Divergence analysis was computed following Mahalanobis (1936). The
individual contribution of characters towards the D2 for each
cultivar was determined and a rank was assigned in the order of magnitude of
contribution, for each character. The characters which contributed maximum were
ranked 1 and the character which contributed least was ranked the last. Ranks
of each character for all the cultivars were added to generate rank totals.
Genotypes were grouped into clusters following TocherÕs method as described by
Rao (1958)
RESULTS AND DISCUSSION
Components
of variance revealed a wide range of variability for all the characters.
Variance arising due to differences among genotypes were highly significant for
all the characters (Table-1). Days to 50% silking ranged from 71 days (C15)
to 87 days (Pul-Tral, 26) with a population mean of 78 days, whereas, days to
50% anthesis ranged from 69 days (Bar-Bandipora, 33) to 85 (Sgr-Sonamarg, 16).
Pul-Malangpora, 30 cultivar recorded minimum days for husk browning (131days),
whereas, maximum days were recorded by Bar- Bandipora, 33 (148 days).
Population mean for this trait was recorded as 140 days. Most of the local
cultivars were observed to be early as compared to high yielding composites.
Check recorded a range of 136-143 days for husk browning. Irrespective of the
origin, plant height ranged from 118.50cm (Sgr-Wangat, 12) to 218.50cm
(Bud-Khag, 3) with a population mean of 185.91 cm. similar trend of cob samples
collected from district Srinagar and Budgam was recorded for minimum and
maximum ear height (99.50 cm). The mean ear height was recorded as 81.04 cm. Ear length which is an important
yield attributing trait was minimum in case of local cultivars (7.93cm) and
maximum in checks (20.02 cm). Over all mean for each length was recorded as
12.98 cm. A wide range of variability was recorded for yield (kg/ha). Highest
yielder (C6) recorded an yield of 5828.50 kg/ha, whereas, a local
cultivar for district Pulwama (Pul-Turkwangan, 29) recorded the lowest yield
(1330.50). Average population yield was recorded as 2052.11 kgÕs/ha. It should
be possible to isolate superior genotypes during the selection process.
Success
of breeder in changing the character of population depends upn the degree of
correspondence between the genotypic and phenotypic values. Heritability has
been used as a direct selection parameter to improve the efficiency of the
process. The measure of heritability coupled with genetic advance provides
useful information regarding the performance of selective population in
comparison to the base population. Such a grain also depends upon the extent of
genetic variability in the base population (Comstock and Robinson, 1952). The
result revealed higher broad sense heritability value for all the traits
excepting days to 50% anthesis (0.51). The results are in agreement with
reports of Singh et al. (1995) and
Kumar and Satyanarayana (2001). The genetic advance was high for grain yield
(1074.03) followed by plant height (27.97) and ear height (22.95). For rest of
the traits it was low ranging from 8.73 (days to 50% silking) to 3.63 (ear
length). Low to medium estimates of genetic advance for maturity traits were
also reported by Viola et al (2003).
Mahalanobis
D2 statistics revealed that values of V statistics (measuring WilkÕs
criteria) were high and significant indicating presence of substantial
genotypic diversity in the material. Classification of local maize cultivars
resulted into grouping of 54 genotypes into 8 clusters with distribution of
checks in 4 different clusters. Cluster 1 accomodated maximum number of
genotypes (18) followed by cluster 3 (15), cluster 2 (12) and cluster 4(5).
Rest of the clusters were monogenotypic. Considering the grouping of cultivars
into different clusters, it was observed that cultivars presently grown in
different maize growing areas had no tendency to be grouped together in the
same cluster, revealing that there was no parallelism in the geographical
genetic diversity. High yielding cultivars were grouped in different clusters.
Among local cultivars Bar-Bandipora, 33 and Ant-Verinag, 44 recorded maximum
grain yield and were grouped in cluster 3 and cluster 1, respectively. Whereas,
among checks C6 recorded maximum grain yield with its distribution
in cluster 6 (Table -2).A perusal of Table-3 revealed maximum inter cluster
distance of 16309.19 between cluster 6 and cluster 7, followed by1268.67
(cluster 7 and cluster 8) and 10126.78 (cluster 3 and cluster 8). Minimum inter
cluster distance of 1100was recorded between checks and local cultivars.
Clusters with maximum number of cultivars revealed minimum intra cluster
distances, cluster 4 recorded maximum intra cluster distance of 1104.10
followed by cluster 3 (1097.50). Cluster 1 with maximum number of genotypes
revealed minimum intra cluster distance (603.90). Cluster 3 with maximum inter
cluster distance accommodating Pul-Tral, 25 also showed high intra cluster
distances. Thus it is clear that tremendous potential exists for intercrossing
the allelic resources present in these adopted local cultivars into high
yielding composites through a systemic breeding and selection approach so as to
recover high yielding recombinants possessing also early maturity and
resistance to biotic and abiotic stress.
Cluster mean analysis (Table-4) indicated that clusters
containing solitary cultivars mostly differed for all the traits excepting for
ear length . The highest cluster mean for days to 50% silking (95.50), days to
50% anthesis (93.0) and ear height (123.0) was exhibited by cluster 6
accommodating high yielding composite C6. Local cultivar Pul-Tral,
25 from cluster 7 recorded maximum cluster mean for husk browning (194.50),
plant height (162.00) and ear length (16.65). Super-1 for cluster 8 recorded
maximum cluster mean (5851.00) followed by cluster 6 (5763.00) for grain yield,
however, among local cultivars maximum cluster mean (493.50) was recorded by
cluster 5. This could have resulted from variation among these cultivars for
various characters containing distinctiveness to these cultivars so as to make
them occupy different cluster differences among them. This situation however,
brings us to a very important consideration that grouping based on total D2
could be relied upon only when the characters of major importance like yield
and maturity are taken into consideration Datta and Mukherjee (2005).
Traits contributing maximum to the divergence of the local
maize cultivars (Table-5) were observed to be ear length (60.59) followed by
grain yield (33.3) and husk
browning (4.47), whereas rest of the traits made negligible contribution to the
divergence. It is proposed that traits contributing maximum towards the D2
value, need to be given great emphasis for deciding on the cluster to be chosen
for the purpose of further selection and choice of parents for hybridization.
similar results for ear length have been reported by Datta and Mukherjee
(2005).
REFERENCES
Ahloowalia, B.S. and Dhan,
N.L. 1963. Effect of genetic diversity in combining ability of
inbred lines of maize. Indian J. Genetic., 23: 158-162.
Hallauer, A. R. 1972. Third
phase in the yield evaluation of synthetic varieties of maize. Crop Sci., 12; 16-18.
Morishima, H. and Oka, H.I.
1960. The patterns of interspecific variation in the genus Oryza: its quantative representation by
statistical methods. Evolution, 14: 153-165.
Rao, C. R. 1958. Bengal
anthropometric survey, 1945: A statistical study.Sankhya,19: 201-408.
Blackith, R. E. and Reyment,
R. A. 1971. Mutivariate morphometrics. Academic Press, London New York. pp.111-132.
Hussaini, S.H., Goodman, M.
M. and Timoty, T.H. 1977. Multivariate analysis and the geographical
distribution of the world collection of finger millet. Crop Sci., 17: 257-263.
Mahalanobis, P.C. 1936. On
the generalized distance in statistics. Proc. Nat. Inst. Sci. India, 2: 49-55.
Johnson, H.W., Robinson, H.
F. and Comstock R.E. 1955. Estimates of genetic and environment variability in
soyabean.Agr. Jr., 47: 214-318.
Datta, D. and Mukherjee,
B.K. 2004. Genetic divergence among maize (Zea mays) inbreds and restricting traits for group constellation. Indian
J. Genet. 64(3): 201-207.
Kumar, P.P. and
Satyanarayna, E. 2001. Variability and correlation studies of full season
inbred lines of maize. Journal of Research, ANGRAU., 29(1) : 71-75.
Comstock, R.E. and Robinson,
H.F. 1952. Estimation of average dominance of genes. pp. 494-516. In Heterosis
(ed) J. W. Gowen. Iowa State College.
Singh, G. Singh, M.and
Dhiman, K. R. 1995. Genetic analysis of maize in Sikkim. Indian Journal of
Agricultural Sciences., 65(4): 293-294.
Viola, G., Ganesh, M., Reddy,
S.S. and Kumar, C.V.S. 2003.Study on heritability and genetic advances in elite
baby corn (Zea mays) lines. Progressive
Agriculture., 3(2): 127-128.
Table-1: Components of variance for
maturity, morphological and yield related traits in local maize cultivars.
|
Components
of variance |
Days
to 50% silking
|
Days
to 50% anthesis |
Days
to Husk Browning
|
Plant
Height (cm) |
Ear
Height (cm) |
Ear
Length (cm) |
Yield
(Kg/ha) |
|
σ2p |
26.30 |
26.18 |
27.94 |
189.74 |
127.71 |
3.12 |
271878.74 |
|
σ2g |
21.74 |
13.26 |
21.93 |
187.08 |
125.91 |
3.12 |
271855.22 |
|
PCV |
6.52 |
6.62 |
3.78 |
7.41 |
13.94 |
|
12.93 |
|
GCV |
5.92 |
4.72 |
3.35 |
7.35 |
13.84 |
10.09 |
12.93 |
|
h2 |
0.82 |
0.51 |
0.78 |
0.98 |
0.98 |
0.99 |
0.99 |
|
Genetic
Advance |
8.73 |
5.34 |
8.54 |
27.97 |
22.95 |
3.63 |
1074.03 |
|
Genetic
Advance as % of mean |
11.09 |
6.91 |
6.11 |
15.04 |
28.31 |
20.77 |
26.63 |
|
Mean |
79.00 |
77.00 |
185.91 |
140.00 |
81.04 |
12.98 |
2032.11 |
|
Range
|
71.00 to 87.00 |
71 to 85 |
118.90 to 218.50 |
131 to 148 |
48.50 to 99.50 |
7.93 to 20.02 |
1330.50 to 5428.50 |
Table
2: Classification of local maize
cultivars into different clusters
|
Cluster
|
Cultivars
included |
|
Cluster
1 |
35,
39, 3, 23, 22, 4, 5, 45, 51 C8, 18, 43, 34, 42, 24, 8, 15, 36, 44 |
|
Cluster
2 |
9,
41, 1, 10, 47, 14, 50, 16, 52, 27, 17, 26 |
|
Cluster
3 |
19, 32, 29, 31, 30, 48, 11, 12, 20, 7,
13, 38, 40, 21, 33 |
|
Cluster
4 |
2,
49, 46, 6, 37 |
|
Cluster
5 |
28 |
|
Cluster
6 |
53 |
|
Cluster
7 |
25 |
|
Cluster
8 |
54
Super-1 |
Bd- Khag1, Bd- Khag2, Bd- Khag-3, Bd-Yusmarg4 , Bd-Neilnag5,
Bd-Yusmarg6, Bd-Dalwash7, Bd-Dalwash8, Bd-Kral Pathsia9, Bd-Kral Pathsia10
Sgr-Khag 11, Sgr-Wangat-12, Sgr-Satrain 13, Sgr-Babanagri 14,
Sgr-Dara 15, Sgr-Sonamarg 16, Sgr-Sonamarg 17, Sgr-Gund 18, Sgr-Gund 19,
Sgr-Gutlibagh 20.
Pul-Shopian-21, Pul-Shopian-22, Pul-Balpora 23, Pul-Malangpora 24,
Pul-Tral 25, Pul-Tral 26, Pul-Tral 27, Pul-Turkwangam 28, Pul-Turkwangam 29,
Pul-Malangpora 30.
Bar-Uri 31, Bar-Gurez 32, Bar-Bandipora 33, Bar-Bandipora 34,
Bar-Pattan 35, Bar-Wagoora 36, Bar-Wagoora 37, Bar-Tangmarg 38, Bar-Fareozpur
39, Bar-Uri 40.
Ant-Qazigund 41,
Ant-Dooru 42, Ant-Verinag 43, Ant-Verinag 44, Ant-Kulgam 45, Ant-Pumbai
46, Ant-Pahalgam 47, Ant-Pahalgam 48, Ant-Mattan-49, Ant-Kokernag 50
Table3: Mean inter and intra cluster distances (D2)
among the local maize cultivars
|
Cluster
No |
Cluster 1 |
Cluster 2 |
Cluster 3 |
Cluster 4 |
Cluster 5 |
Cluster 6 |
Cluster 7 |
Cluster 8 |
|
Cluster
1 |
603.90 |
1804.52 |
3533.11 |
2933.02 |
1805.65 |
2551.22 |
2551.22 |
5216.58 |
|
Cluster
2 |
|
941.13 |
5564.65 |
6582.96 |
1690.48 |
6389.42 |
4166.20 |
3437.39 |
|
Cluster
3 |
|
|
1097.50 |
2403.78 |
1954.51 |
3049.18 |
10126.78 |
3876.44 |
|
Cluster
4 |
|
|
|
1104.10 |
4057.38 |
8036.76 |
6788.13 |
8458.17 |
|
Cluster
5 |
|
|
|
|
0.00 |
2189.46 |
7009.43 |
1132.00 |
|
Cluster
6 |
|
|
|
|
|
0.00 |
16309.19 |
1100.00 |
|
Cluster
7 |
|
|
|
|
|
|
0.00 |
12683.67 |
|
Cluster
8 |
|
|
|
|
|
|
|
0.00 |
Table 4: Cluster means for different traits in local maize cultivars adopted to different temperate conditions of Kashmir
|
Cluster No |
Number of cultivars in cluster |
Yield (Kg/ha) |
Days
to Husk Browning |
Days
to 50% silking |
Days
to 50% anthesis |
Plant
height (cm) |
Ear height (cm) |
Ear length (cm) |
|
1 |
18 |
3983.72 |
181.44 |
86.81 |
83.61 |
152.64 |
83.14 |
18.10 |
|
2 |
12 |
4665.25 |
173.29 |
86.88 |
85.25 |
157.83 |
87.63 |
19.55 |
|
3 |
15 |
4581.60 |
173.50 |
86.33 |
83.57 |
151.73 |
85.00 |
15.63 |
|
4 |
5 |
3585.60 |
167.30 |
89.30 |
87.00 |
155.30 |
88.50 |
15.58 |
|
5 |
1 |
4923.50 |
167.00 |
91.50 |
82.00 |
157.50 |
124.00 |
17.84 |
|
6 |
1 |
5763.00 |
189.00 |
95.50 |
93.00 |
156.50 |
123.00 |
16.65 |
|
7 |
1 |
3104.50 |
194.50 |
82.50 |
81.50 |
162.00 |
99.00 |
19.53 |
|
8 |
1 |
5851.00 |
163.50 |
81.50 |
81.50 |
158.60 |
94.50 |
18.27 |
Table 5: Contribution of different maturity, morphological and yield related traits towards total divergence among local maize cultivars
|
Traits |
Number of times appearing first in the rank |
percent contribution towards total divergence among the material studied |
|
Silking |
10 |
0.70 |
|
Anthesis |
0 |
0.00 |
|
Plant height |
64 |
4.47 |
|
Husk |
10 |
0.70 |
|
Ear height |
3 |
0.21 |
|
Ear length |
8.67 |
60.59 |