Agro-Morphological Characterization of Pigeonpea (Cajanus cajan (L.) Millsp.) germplasm

Author: Patel P.R.*, Padhiyar B.M., Sharma Manish, Padmavati G. Gore and Patel M.P.

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Abstract

Genetic variability is prerequisite for any crop improvement programme and phenotypic characterization of crop genetic resources generates important information for plant breeders, therefore the present investigation was undertaken in which three hundred five pigeonpea accessions were evaluated and morphological characterization was carried out during kharif 2021 at Pulses Research Station, SDAU Sardarkrushinagar (Gujarat) under Consortium Research Platform on Agro-biodiversity. Out of three hundred five accession one accessions did not germinate. Majority of the accessions showed very good early plant vigour (212 acc.), semi spreading plant growth habit (292 acc.), indeterminate plant type (304 acc.), yellow flower colour (275acc.), green stem colour (300 acc.), glabrous leaf pubescence (304acc.), sparse streak (198 acc.), glabrous pod pubescence (304 acc.), cylindrical pod shape (304 acc.), green and purple pod colour (293 acc.), very large seeded (19 acc.), plain seed colour pattern (283acc.), medium seed eye width (40 acc.), orange base seed colour (96acc.), globular seed shape (38 acc.) and very low biotic stress susceptibility (4 acc.). Wide range of variability was observed for days to flowering, primary branches, days to maturity and 100 seed weight (9.0-14.0g). Considering the wide range of variability for qualitative and quantitative characters, germplasm has high potential which can be utilized in future pigeonpea improvement programmes. This study thus provides a foundation for the selection of parental material for genetic improvement.

Keywords

Pigeonpea, Agro-biodiversity, Characterization, Germplasm.

Conclusion

Information on genetic variability among the existing pigeonpea genotypes will increase the efficiency of crop genetic improvement. The present study affirmed that characterization and evaluation of 305 accessions of pigeonpea for agronomic traits are important in discerning genetic variability that can be exploited in plant breeding. The phenotypic traits therefore provide a useful measure of genetic distances among the pigeonpea genotypes and will enable the identification of potential parental materials for future breeding efforts especially in identifying donors for economic traits.

References

INTRODUCTION Pigeonpea [Cajanus cajan (L.) Millsp.] is the second most important pulse crop of India after chickpea, commonly known as arhar, red gram and tur.It is an important crop for millions of people living in dry regions of the world as it is a multipurpose crop that integrates crop and livestock production, thus contributing to food security (Ayenan, 2017). It is a rich source of protein, carbohydrate, vitamins, lipids and certain minerals. Compared to other food legumes, breeding in pigeonpea has been more challenging due to various crop specific traits and highly sensitive nature to biotic and abiotic stresses. Germplasm is vital resource in generating new plant types having desired traits that help in increasing crop production with quality and thus improve the level of human nutrition. The search for diversity in a germplasm collection is a way of identifying desirable genes for future utilization in breeding, where the diversity in crop species usually depends on mutation, recombination, selection and genetic drift (Bhandari et al., 2017). Germplasm characterization and documentation are important activities in plant genetic resources management and it eases the data retrieval and short listing of accessions for the genetic improvement. Germplasm utilization is increased if detailed characterization of data is obtained for individual accessions, which should include qualitative and quantitative phenotypic traits, genotypic data and responses to biotic and abiotic stresses. Detailed characterization of data is lacking in pigeonpea collections, which emphasizes the need for further data collection and characterization which are the pre-requisite for the utilization of available diversity in the pigeonpea improvement programme. Plant genetic resources are invaluable source of genes and gene complexes for yield and several biotic and abiotic factors and provide raw materials for further genetic improvement (Patel et al., 2021). Therefore, the collection of pigeon pea germplasm and its proper characterization, evaluation, conservation and utilization in improvement programmes assume great significance, especially in view of climate change. Genetic diversity in a crop species can be studied using different methods including morphological and/or phenotypic, biochemical and molecular markers (Mehmood et al., 2007). In the past, morphological traits, both qualitative and quantitative have been successfully used to study genetic diversity in pigeonpea (Kallihal et al., 2016; Navneet et al., 2017; Zavinon et al., 2019). A positive association between two desirable traits makes the job of the plant breeder easy for improving both traits at a time. The present investigation was carried out to analyze the genetic divergence existing in the crop. This information is highly useful for breeders in the selection of parents and breeding material for the development of high yielding varieties of pigeonpea. Hence, the present study was under taken at Pulses Research Station, Sardarkrushinagar Dantiwada Agriculture University, Sardarkrushinagar through the All India Coordinated Research Project on Pigeonpea under Consortium Research Platform on Agro biodiversity to characterize 305 accessions of pigeonpea germplasm (Table 1) during kharif 2021.This study aims to assess the morphological diversity in a collection of pigeon pea accessions with the objective of evaluating the phenotypic variations. MATERIAL AND METHODS The trial was conducted in Augmented Block Design (ABD) during Kharif 2021 at Pulses Research Station, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, Gujarat which is located at 72.12 º E longitude, 24.9 º latitude and 154.5 m altitude above MSL. These accessions were divided into eight blocks and each block consisted of 50 accessions with two check varieties viz., BDN 711 and GT 101. The soil of the field was sandy loam in texture with pH value of 7.7 to 8.00 having good physical and chemical properties (Organic Carbon = 0.07, K2O = 234.0 kg/ha and P2O5 = 56.0 kg/ha). The experimental unit was a two-row plot of 4.0 m long, spaced at 0.60 m apart. Fertilizer dose of 25:50:00 (NPK) were applied as basal. Plots were thinned down after two weeks of crop emergence and plant-to-plant distance of 0.20 m was maintained. The experimental year showed different temperature regimes, humidity, rainfall and sunshine hours during the crop duration (Table 2). All the other recommended agronomical packages and practices were followed to raise a good crop. Data was collected based on the minimal descriptors released by NBPGR, New Delhi (Mahajan et al., 2000) and the list of pigeonpea descriptor released(Anonymous,2020). Five representative plants in each accession were tagged for recording the qualitative and quantitative traits (Anonymous, 2020). Plant protection measures were taken as and when required to raise a good crop. RESULT AND DISCUSSION Genetic diversity analysis in pigeonpea is crucial for effective breeding and germplasm conservation. Previous studies examined the genetic diversity of the crop using morphological and agronomic traits (Manyasa et al., 2008). The preliminary characterization of 305 accessions of pigeonpea germplasm were worked out for 20 agro-morphological characters viz., early plant vigour, plant growth habit, plant habit, days to flowering, base flower colour, stem colour, leaf pubescence, streaks pattern, pod pubescence, pod shape, pod colour, days to 80% maturity, 100 seed weight (g), seed colour pattern, seed eye width, base seed colour, seed shape, biotic stress susceptibility, plant height and pod size. Wide range of variability in both quantitative and qualitative characters was observed (Patel et al., 2020). The range of variability and frequency observed in qualitative characters are given in Table 3. Majority of the accessions showed very good early plant vigour (212 acc.), semi spreading plant growth habit (292 acc.), indeterminate plant habit (304 acc.), medium days to flowering (69 acc.), late days to flowering (228 acc.), yellow flower colour (275acc.), green stem colour (300 acc.), glabrous leaf pubescence (304acc.), sparse streak (198 acc.), uniform streak pattern (20 acc.), glabrous pod pubescence (304 acc.), cylindrical pod shape (304 acc.), green and purple pod colour (293 acc.), mid early maturing (30 acc.), medium maturity (119 acc.), very large seed (19 acc.), plain seed colour pattern (283 acc.), medium seed eye width (40 acc.), orange base seed colour (96acc.), globular seed shape (38acc.) and very low biotic stress susceptibility (300 acc.), such germplasm with resistance or tolerance to biotic stress can be an asset to plant breeder in developing resistant cultivar. The wide range of variation was observed for early plant vigour (Good to Very good), plant growth habit (Erect & compact to semi spreading), plant habit (Indeterminate), plant height (199-226 cm), days to flowering (125-168 days), base flower colour (Yellow to orange yellow), primary branches (7.0-10.0), days to maturity (175-218 days), stem colour (Green), leaf pubescence (Glabrous), streak pattern (Sparse streak to uniform coverage of second colour), pod pubescence (Glabrous), pod shape (Cylindrical), pod colour (Green to green & purple), pod size (Short to long), 100 seed weight (9.0-14.0g), seed colour pattern (Plain to Speckled), seed eye width (Narrow), base seed colour (White to dark purple), seed shape (Oval to elongate), pods per plant (84-178), pod length (4.0-6.0 cm) and seeds per pod (4.0-5.0) showed wider ranges. The preliminary characterization and descriptive statistics revealed that seed yield, plant height, 100 seed weight, pod length, days to 50% flowering and seeds per pod were the most variable characters. Earlier reports by Kimaro et al. (2021); Ramesh (2017); Sahu et al. (2018); Rupika and Kannan (2014); Upadhyaya et al. (2007); Upadhyaya et al. (2005) have also exhibited the presence of variation for different characters in pigeonpea germplasm accessions. Mean data revealed that some of the accessions showed outstanding performance for different agro-morphological traits viz., plant height IC525757 (162.0 cm) and IC527696 (255.0 cm), primary branches per plant IC261341 (5.2) and IC468389 (13), pods per plant IC525303 (31.4) and IC298609 (225), pod length IC498473 (2.92 cm) and IC525757 (6.54 cm), seeds per pod IC468472 (3.2) and bold seed IC343916. These accessions with potential for different agro-morphological traits may be utilized in crop improvement program through hybridization and selection for developing superior genotypes for yield as well as for biotic and abiotic resistance.

How to cite this article

Patel P.R., Padhiyar B.M., Sharma Manish, Padmavati G. Gore And Patel M.P. (2022). Agro-Morphological Characterization of Pigeonpea (Cajanus cajan (L.) Millsp.) germplasm. Biological Forum – An International Journal, 14(2a): 598-602.