IJERD – International Journal of Environmental and Rural Development (2021) 12-1

Research article
erdCharacterization and Diversity of Selected Maize (Zea maysL.) Genotypes Using Qualitative Traits
SAN KYI*Yezin Agricultural University, Nay Pyi Taw, Myanmar
Email: sankyi747@gmail.com

KYAW KYAW WIN
Pro-Rector’s Office of Administration, Yezin Agricultural University, Nay Pyi Taw, Myanmar

HLA THAN
Pro-Rector’s Office of Academic, Yezin Agricultural University, Nay Pyi Taw, Myanmar

SOE WIN
Department of Plant Breeding, Physiology and Ecology, Yezin Agricultural University,Nay Pyi Taw, Myanmar

NYO MAR HTWE
Advanced Center for Agricultural Research and Education, Yezin Agricultural University,
Nay Pyi Taw, Myanmar
Received 22 December 2020

Accepted 30 June 2021(*Corresponding Author)

Abstract Phenotypic traits qualitatively and quantitatively are helpful as a preliminary
evaluation of maize genetic diversity and provided practical and critical information required
characterizing genetic resources. To find out the varietal characterization and grouping withsimilarity, fifty maize genotypes including hybrids and inbreds were examined in thisexperiment. This experiment was carried out in a randomized complete block design with three
replications during wet season from June to October, 2019, at Maize and other Cereal Crops
Research Section, Department of Agricultural Research (DAR), Yezin, Nay Pyi Taw, Myanmar.
The qualitative characters were recorded at different growing stages according to theInternational Union for the Protection of New Varieties of Plants (UPOV) Test Guide line (TG).
The agglomerative cluster analysis was computed using Ward’s hierarchical algorithm based ofqualitative characters. According to the results, diverse qualitative traits were observed among
the tested genotypes and genotypes varied different qualitative traits with different frequencies.
Thus, comparisons of qualitative traits were made to know the extent of variation among maize
varieties under investigation to estimate the genetic diversity. The tested maize genotypes could
be grouped five clusters based on qualitative traits. Although some maize genotypes collectedin an area are included in different groups because of the different characteristics they pose.
Since qualitative characters have less environmental influences, these traits could be used forDistinctness, Uniformity and Stability (DUS) test and Value for Cultivation and Use (VCU)
testing of plant varieties. Thus, the application of morphological markers according to UPOV
descriptor could contribute to more efficient selection of parental pairs in the early generationsof testing.
Keywords characters, cluster, maize genotypes, variationⒸ ISERD

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INTRODUCTION
Maize (Zea mays L.) is the world’s third most important cereal, widely used in poultry and foodindustries next to wheat and rice. As it has higher yield potential than any other cereals, it is referred toas “miracle crop” or the “queen” of cereals. Maize is grown both as food for human beings and fodderfor animals (Malhotra, 2017). In Myanmar, maize is the second most important cereal after rice. In
2017-2018, maize growing area is 504,000 ha and production is 1940,000 MT. As demand for maize
has increased annually since 2009, the maize growing area has expanded year by year (DoP, 2018).
Most of cultivars grown in Myanmar are introduced hybrid varieties and these varieties are registeredaccording to the Seed Law and Regulation. Although the registered varieties are increasing year byyear, the procedure on clarification as a new variety is weak. Awareness of genetic diversity among
elite breeding materials or adapted cultivars has an important role in the improvement of crop plants.
Many tools are now available to study the relationships among the cultivars, including various
types of molecular markers; however, morphological characterization is the first step in the description
and classification of germplasm (Smith and Smith, 1989). There is an important role of morphologicaldata in the management of genetic resources that are conserved in ex-situ gene-banks. Thecharacterization and grouping of lines helps the breeders to avoid duplication in sampling populations
and to aid in the identification of varieties and hybrids (Madhukeshwara and Sajjan, 2015). Although
there are the ways to collect the morphological character by using International Board for Plant GeneticResources (IBPGR) descriptor and International Union for the Protection of New Varieties of Plants(UPOV) Test Guide line (TG), collection of the data according to UPOV TG is better forcharacterization of the genotypes which are used to set up reference varieties in TG preparation, andDistinctness, Uniformity and Stability (DUS) testing. The inventory and agro-morphologicalcharacterization of these genetic resources (improved varieties and local’s accessions) are essential toprovide a sound database on the characteristics of the maize (Salami et al., 2015). Therefore, thisexperiment was conducted to characterize qualitative characters of maize and to identify similarity
among maize genotypes.
METHODOLOGYThis experiment was carried out during the wet season from June to October, 2019, at Maize and otherCereal Crops Research Section, Department of Agricultural Research (DAR), Yezin Nay Pyi Taw,
Myanmar which was located at 19° 49' 33˝ N; 96° 16 44˝ E; 102 m above sea level. In the present
investigation, 38 hybrids (developed from DAR and imported by private companies) and 12 inbredlines and open pollinated varieties (OPVs) (developed from DAR, Yezin) were utilized. These
genotypes are selected based on the most recommended for importation in 2018-19, as new varieties
approved by 10th-14th National Seed Committee (NSC) and currently grown in Regions and Divisions.
All tested genotypes were evaluated in Randomized Completely Block Design with threereplications. Each entry (genotype) was grown at a spacing of 75 cm × 25 cm, in a plot size of tworows with 4 m length. Two seeds were sown in each hill and thinning was done 14 days after sowing
and single plant per hill was left. For fertilizer application, Urea, Triple Super Phosphate and Muriateof Potash were applied as basal at the rate of 123.5 kg ha-1, 123.5 kg ha-1 and 61.75 kg ha-1,respectively. Then, the first and second sides dressing of 61.75 kg ha -1 Urea, 30.86 kg ha-1 Muriate ofPotash were applied three weeks after sowing and five weeks after sowing, respectively. Intercultivation was done two times; just before the fertilizer applications which control weeds and also
improve soil aeration. The qualitative parameters were recorded on each tested genotype in each
replication on five representative plants according to UPOV test guidelines. The qualitative characters
were recorded at different growing stages following UPOV TG. The agglomerative cluster analysisⒸ ISERD157

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was computed based on qualitative and morphological characters using Ward’s hierarchical algorithm
according to the procedure as described by Singh and Chaudhary (1977).
RESULTS AND DISCUSSION
Characterization of Maize Genotypes
The qualitative traits of tested maize genotypes were classified according to UPOV test guidelines.
Variations of 18 qualitative characters in 50 maize genotypes are shown in Fig. 1. Some distinctive
characteristics of tested maize genotypes are presented in Plate 1. The anthocyanin coloration of firstleaf sheet possessed five groups such as absence, weak, medium, strong and very strong color
anthocyanin. There were 29 genotypes (58%) having strong anthocyanin, 18 genotypes (36%) having
medium and 3 genotypes (6%) having weak anthocyanin. There was no genotype with absence ofanthocyanin and very strong anthocyanin coloration. In shape of first leaf apex, the maximum
percentage of genotypes exhibited rounded to speculate type (78.00%) and the minimum accessions
showed round apex type (22%) of leaf apex shape. The intensity of green color in foliage wasclassified into three groups such as light, medium and dark green for tested maize genotypes. Of thetotal, 28 genotypes showed medium green color foliage (56%), 14 genotypes (28%) had dark green
foliage and other 8 genotypes were observed (16%) light green foliage. The undulation of margin in
first leaf blade in tested genotypes was classified as absence, intermediate and strong. Among thegenotypes, 25 genotypes possessed intermediate undulation of margin of leaf blade, 15 genotypes wereabsent and the rest 10 genotypes had strong undulation leaf blade margin.
Five characters regarding with tassel were examined in this study: tassel anthocyanin coloration at
the base of glume, anthocyanin coloration of glume excluding base, anther anthocyanin coloration, theangle between main axis and lateral branches and curvature of lateral branches of tassel. In this result,different genotypes possessed different tassel characters. The types of spikelets density in tassel wasclassified into three types. Among the 50 genotypes, most were medium density of spikelets (66%) andthe rest was moderately lax (34%), and there was no moderately dense density of spikelets. In,
anthocyanin coloration of silk of ear, no anthocyanin (19 genotypes = 38%), weak anthocyanin (23genotypes = 46%), medium anthocyanin (8%) and strong anthocyanin (8%) colors were found among
the 50 genotypes. Among the maize genotypes studied, 30 genotypes (60 %) were found no purple
anthocyanin in brace root, 14 genotypes (28%) had weak anthocyanin, 4 genotypes (8%) had medium
color and 2 genotypes (4%) were noticed as strong anthocyanin.
Leaf sheath and stem (internode) anthocyanin color were classified five groups as absent or very
weak anthocyanin, weak, medium, strong and very strong. Leaf sheath anthocyanin was dispersed at allgroups as very strong anthocyanin color (16%), strong anthocyanin color (32%), medium anthocyanin
color (30%), weak anthocyanin color (14%) and very weak or absence of anthocyanin color (8%). In
stem color, absence of anthocyanin (68%), weak anthocyanin (24%), medium (4%) and light strong
anthocyanin (4%) were observed among the genotypes. There was no genotype with strong
anthocyanin color in internode color. The shape of maize ear was characterized as conical, conicalcylindrical and cylindrical. Most of the tested genotypes had conical-cylindrical type of ear (62%),
followed by cylindrical type of ear (34%) and the rest (4%) had conical type of ear.
In types of grain, UPOC TG showed nine types: flint, flint like, intermediate, dent-like, dent,sweet, pop, waxy and flour. In this study, four types of grain were observed among the genotypes.
Most of the genotypes possessed flint like grain showing about 44% of total. Nineteen out of 50 (38%)
showed intermediate type of grain, 16% had flint of grain, and the rest genotype about 2% had dent
type of grain. There were 10 types of color of grain top such as white, yellowish white, yellow,yellowish orange, orange, red orange, red, purple, brownish and blue black color. In this study, only
four types of color of grain top were observed among the tested genotypes with the frequencies of 2%Ⓒ ISERD

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in yellowish white, 26% in yellow, 56% in yellowish yellow and 16% in orange. No more color ofgrain top was examined. Although five types of anthocyanin coloration of glumes of cob wereclassified, only two distinct colors with distinct frequencies like absent anthocyanin (96%) and medium
anthocyanin (4%) were observed among the tested maize genotypes. According to the results,
comparisons of qualitative traits were made to know the extent of variation among maize varieties
under investigation to estimate the genetic diversity.

Fig. 1 Variation of different qualitative characters in maize genotypes
Note: 1-anthocyanin coloration of first leaf sheet, 2-apex shape of first leaf, 3-intensity of green infoliage, 4-undulation of leaf blade margin, 5-anthocyanin coloration at base of tassel glume. 6anthocyanin coloration of tassel glumes, 7-anthocyanin coloration of anthers, 8-tassel angle between
main axis and lateral branches, 9-curvature of lateral branches, 10-anthocyanin coloration of silks.
11-anthocyanin coloration of brace roots, 12-density of spikelets, 13-anthocyanin coloration of leaf
sheath, 14-anthocyanin coloration of internodes, 15-ear shape, 16-type of grain, 17-grain color, and18-anthocyanin coloration of glumes of cobⒸ ISERD

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Cluster analysis of maize genotypes
The cluster analysis, using WARD method based on the squared Euclidean distance criteria, wasconducted for measuring genetic diversity and relatedness among the studied genotypes by using
qualitative characters (Fig. 2). The studied maize hybrids were grouped into five clusters, showing theexistence of considerable genetic diversity among 50 maize genotypes. Some of the hybrids of thesame geographical region (source) were observed in different groups. Maximum number of genotypes
were grouped in Cluster III (16 genotypes), followed by cluster IV (14 genotypes) and Cluster I (12genotypes) whereas cluster V contained the least number of genotypes (only three genotypes) followed
by cluster II (five genotypes) (Table 1). It can be concluded that the genotypes present in the same
region were genetically distinct from each other. These results are in accordance with previous findingsof Babic et al. (2016) who concluded that the grouping of maize lines based on the scale-measured
characteristics was not in accordance with the information of their origin and even related line pairs
were not grouped in the same cluster.

Fig. 2 Dendrogram of maize genotypes based on morphological distances by a visual assessmentof the group of plants and single measurement of individual plants or part of plants
Table 1 Cluster based on qualitative characters
ClusterNo.

I12II

5III

16IV14V

3

Name of genotypes
03P13, AA-757, Armo 265, Armo 9034, Asia Seed A44, Asia Seed A55, CP 809, DK9955, Hawaii Norma l8, KICF12003, Yezin Hybrid, YZCI 14-060
AA 747, AA737, Asia Seed A11, Asia Seed A88, Asia Seed A99
Armo 528, Armo 9698, GoldenTiger 029, GT 709, GT 722, Hanumar SP333,Hanumar
SP888, KMHE 3550, KMHE 422, LG 772, NK 625, Premier 515, Shwe Mye 10, TSF
1707, TSF 1898, YZI10-095
Armo 139, C7, CP 111, CP 808, NK 621, PAC 999, Premier 518, SD 5059, TSF 1633,
TSF 1818, TSF 555, Yezin Hybrid 10, YZCI 16-019, YZCI 16-049
YZCI16-053, YZI10-054, YZI16-045

Cophenetic correlation coefficient = 0.577Ⓒ ISERD

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CONCLUSION
The total 50 maize genotypes (including hybrids and inbreds) were examined their qualitative
characters. The results showed that genotypes varied different qualitative traits with different
frequencies. The fifty maize genotypes, with the help of cluster analysis, were successfully
characterized and accurately grouped into five clusters with distinct promising features. It should be
noted that some maize genotypes collected in an area are included in different groups because of thedifferent characteristics they pose. Thus, the application of morphological markers according to UPOV
descriptor could contribute to more efficient selection of parental pairs in the early generations oftesting.
APPENDIX
Some distinct qualitative traits of maize from this study were summarized below.

ACKNOWLEDGEMENTS
The authors are grateful to the responsible persons from DOA, DAR and YAU for their kindpermission and collaborating to conduct this study. We acknowledge all the staff of Maize and other
Cereal Crops Research Section, DAR for helping us.
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