Investigating the distinction, uniformity and stability (DUS) of new pinto bean (Phaseolus vulgaris L. cv. ‘Negin’ ) cultivar applying for commercialization

Introduction: Legumes are the second most important source of human food after cereals and the most important source of protein in the world's diet (Rebetzke et al., ۲۰۰۶). High genetic diversity in beans has caused phenotypic diversity in terms of growth habit (limited or unlimited), vegetative characteristics, size, shape and colour of flower, pods and seeds (Vasi et al., ۲۰۰۸). In a research on ۸۹ bean genotypes, it was reported that the characteristics such as number of flowers, number of pods per plant, number of seeds per pod and weight of one hundred seeds were the most effective factors in yield (Keshavarznia et al., ۲۰۱۳). In order to support new plant cultivars and breeders grant rights, it is necessary to compare the candidate cultivar with the existing and known cultivars using morphological traits and, if necessary, molecular traits. New cultivar should have the three conditions of distinction, uniformity and stability in reference traits that to be placed as a new cultivar in the national list of the country's cultivar. This research was carried out in order to evaluate the distinction, uniformity and stability of the distinguishing traits of the new variety of pinto bean (Negin). Materials and methods: This experiment was conducted in order to investigate the distinction, uniformity and stability of Candidate pinto been cultivar (Negin) along with four control cultivars (Sepehr, Sembol, Saleh and Kusha) based on complete randomized block design with three repetitions during two crop seasons (۲۰۲۱-۲۰۲۲ and ۲۰۲۲-۲۰۲۳) in Khomein region. Morphological traits were observed, measured and recorded on ۶۰ plants or parts of ۶۰ plants according to the international guidelines for distinction, uniformity and stability tests in beans. SAS software (version ۹.۱) was used for data analysis and mean comparison of studied data was done with Duncan's multi-range test at ۵% probability level. Results and Discussion: Results showed that Negin candidate cultivar, like Sepehr and Sembol, had a climbing growth type, and in this respect, it was completely different from dwarf Saleh and Kusha control varieties. Negin candidate variety in terms of characteristics of average height of the plant, pod curvature, the shape of the end of the pod, the shape and width of the transverse cut of the seed was similar to the control cultivars (Sepehr and Sembol) and it was different from the studied dwarf cultivars (Kusha and Saleh). The results of the composite variance analysis of the studied quantitative traits showed that the effect of the cultivar factor on all the studied quantitative traits was significant. The results of mean comparison showed that the length of the tip of the terminal leaflet in Negin (Candidate) and Sepehr cultivars was significantly higher than the other studied cultivars. 'Pod length minus tip' of Sembol and Negin (candidate) cultivars were significantly higher than other studied cultivars respectively. 'Pod width' in Sembol cultivar was significantly more than other cultivars, so it seems that Sembol cultivar had larger pods (greater length and width). Sepehr cultivar has a thicker pod than other cultivars and it was distinctly different from the other studied cultivars in this respect. In addition to the fact that Sepehr variety had thicker pod. In general, Negin candidate cultivar along with Sepehr and Sembol cultivars are among the climbing cultivars that have bigger seeds than the unlimited growth cultivars (Kusha and Saleh) and their hundred seed weight were significantly higher. Bean is a polymorphic crop with diverse growth habit (limited or unlimited), diverse vegetative characteristics, diverse flower colour, size, shape and diverse colour of pods and seeds. Therefore, the high genetic diversity has created a high phenotypic diversity among the species of this crop plant. Conclusion: Results of distinction, uniformity and stability (DUS) test showed that Negin candidate cultivar was distinguished from other cultivars. Candidate cultivar (Negin) was completely uniform in terms of studied traits in both years of the test and were eligible for registration. Also, the investigated traits in this cultivar was stable in both years of the test.

کلیدواژه ها:

Bean ، Cultivar ، Distinction ، Morphological traits ، Stability ، Uniformity