A brief study on Agromorphological trait Characterization of chickpea variety’s (Cicerarietinum L.) Germplasm to improve genetic resources in Ethiopia. (Preprint)

Abstract

Chickpea (Cicer arietinum L.) is the third most important food legume and production Following common beans and Faba beans in Ethiopia and the third most important pulse crop in the world [5]. In Ethiopia introduction of improved varieties and crop management practices, chickpea has become increasingly popular. The crop is now cultivated around 0.7 million households over 242,703 hectares (ha) of land, and with averagely 2.058 tons per ha-1 production. Chickpea has emerged as the country’s third most important export crop among legumes, generating US$61 million annually. Chickpea is a versatile and the cheapest crop with multiple benefits for integrated crop-livestock farming systems [24]. It is a crucial source of micronutrients and protein, enhances soil fertility by fixing nitrogen, has a small carbon footprint, helps to mitigate climate change, and is simple to add into crop rotations [3]. India, Pakistan, Mexico, Turkey, Ethiopia, and Myanmar are the top chickpea producing nations throughout the worldwide [13].The crop most likely came from the region that is now southeastern Turkey and the nearby Syrian regions. The suggestion has been made that Ethiopia and India are secondary hubs for the variety of cultivated chickpea [9]. The genetic diversity found in plant genetic resources ensures that genetic development will continue, as well as acting as insurance against unanticipated dangers to agricultural productivity [8]. For the purpose of creating high yielding varieties and preserving their productivity in plant breeding procedures, genetic diversity studies of plants are crucial [24].Screening and selection for crop improvement varieties would be based on the presence of enhanced genotypes, which only depends on the presence of better agronomic traits along with disease resistance, earliness, and high yield [13][24]. Unluckily, despite its nutritional benefits and economic significance, chickpea output is quite low per hectare because improved varieties and technologies developed by the research system in Ethiopia are not being used. This is mostly caused by the poor genetic makeup of the cultivars that are readily available [1],[24]. Any breeding program needs genetic diversity because it gives plant breeders the chance to choose genotypes with high yields. Based on morphological features, which are traditional ways to separate variants based on the observation of external morphological differences in various geographic regions, one way techniques of estimating genetic diversity is based on these differences [7],[8],[24]. Additionally, morphological features are easy to score and inexpensive to use. The landraces displayed significant intra- and inter population heterogeneity in the research of Ethiopian chickpea morphological features [1]. The basis for choosing enhanced crop varieties is provided by its crucial information on the relationships between yield and other important components [24]. Therefore, Characterization plays a crucial role in the identification of accessions or varieties because to the distinctive agro morphological qualities those are crucial for seed production, seed quality, seed certification, and genetic purity. Modern plant breeding and agricultural systems have narrowed the base for the genetic diversity of cultivated chickpea [24]. This study's goal is to evaluate the morphological diversity of the selected chickpea accession varieties by analyzing qualitative and quantitative traits.

This study's goal is to evaluate the morphological diversity of the selected chickpea accession varieties by analyzing qualitative and quantitative traits.

The experiment was conducted at Agdora demonstration site which is located in Eastern Hararghe Zone. Agdora demonstration site is found in Fadis Woreda of Easter Hararghe Zone far away 33km from Harar city and 8km from Fadis Woreda. Thirty two selected chickpea accessions with eight check verities were sown on the growing rainy season on 5th August 2022. All the agronomic practices and data collection were carried out throughout the crop growing and harvesting season. With three replications, a randomized block design (RBD) was adopted. Each accession was planted in five rows with a 3 m2 (1 m x 3 m) plot area, with blocks and plots spaced apart by 1.5 m and 0.65 m, respectively. Using a 0.15m gap between plants, 100 seeds were planted in each plot. Randomly chosen five plants per plot from each accession were tagged and used to capture data on morphological traits. The morphological data recorded on qualitative and quantitative agronomic traits were collected during the cropping season according to descriptors of chickpea. The data recording on qualitative and quantitative characters were listed with its measuring scale and period of time presented. The data collection on qualitative and quantitative characteristics were listed in (Appendix 1&2), respectively, along with the measuring scale and time period used. Using SAS statistical software, the analysis of variance (ANOVA) was done to determine the variation in agromorphological traits [21]. Using straightforward statistical metrics like mean, range, genotypic and phenotypic variances, and coefficient of variations, the variation of each morphological attribute, such as quantitative traits, was assessed.

Qualitative traits characterization of 32 accessions and 2 chick varieties were characterized based on the characteristics described in the Distinctiveness, Uniformity and Stability guidelines. Characterization through morphological traits has been used as a major component for identification of genotypes or cultivar varieties. Identification of any cultivar is not possible based on a single trait where a detailed morphological description of plants and seeds should be characterizing. Nine quantitative traits of accessions along with two check varieties were characterized. 34 accessions were grouped into three clusters (Table 2). Cluster I consisted of twelve accessions that were characterized as dwarf type; least Secondary branch, pod per plant, yield per plant and yield per hectare, whereas medium days to 50% flowering days, days to maturity and primary branch. Cluster II consisted of twenty accessions characterized by maximum days to 50% flowering days, days to maturity, plant height, secondary branch and 100 Seed weight while yield per plot and yield per hectare were characterized as medium and also minimum primary branch. Cluster III consisted of eight accessions that were characterized maximum primary branch, pods per plant, yields per plant, yields per hectare; while medium plant height, secondary branch and 100 Seed weight (TGW) but minimum days to 50% flowering days and days to maturity plant were characterized. Generally Cluster II consists of twenty accessions followed by Cluster I with twelve accessions. Cluster II consisted of maximum accessions indicating that the accession had narrowed genetic divergence among them. The similarity in the parental population, which had evolved, might be the cause of genetic uniformity. However, the unidirectional selection potential for one particular trait or a group of linked traits in several places may produce similar phenotypes which can be aggregated into one cluster irrespective of their geographic origin [12], [17], [24].

To summarized, most accessions were characterized by erect plant growth type and pink flowering color. Accessions were characterized by medium pod length and angular ram’s seed shape. Majority of accessions were characterized by rough seed texture and brown to reddish brown seed color. All accessions were characterized as absences of seed shattering and early flowering date but no late flowering dates were observed. The highest coefficients of variation (CV) were observed for Days to 50% flowering, Secondary branch, 100 Seed weight and Yield per hectare While Primary branch, Days to 75% maturity and Plant height were observed least coefficient of variation. The comparison of Clusters; Cluster I were characterized minimum secondary branch, plant height and 100 seed weight; Cluster II were characterized maximum plant height, secondary branch and 100 seed weight and Cluster III were characterized as maximum pods per plot, yield per hectare and yield per plot. The intra cluster distance ranged from 475 to 953 but a maximum intra cluster distance was found in Cluster III (953).Therefore accessions belongings cluster III were the most divergent. As result analysis significantly strong positive correlation were observed between days to 75% maturity with plant height(r=1.00); while weak and negative correlations were observed between 100 seed weight with yield per plot (r=-0.24) but no correlation was observed between secondary branch with 100 seed weight(r=0.00). Characterizations of 32 chickpea accessions were found talented traits with better yield, Environmental adaptability and resistant compared to the check varieties. When increasing the plot size and block replication number at the same location and environmental conditions, no significant morphological variation of accessions were occurred. This study could be used in the future breeding program for improvement of chickpea varieties and hybridizing desired genetic traits used to address the challenge for the development of climate smart crop Environments breeder varieties.