Karyotype analysis of Indian lentils through EMA based Giemsa staining

Abstract

Crop improvement, conservation and utilization of plant genetic resources has benefited from chromosomal studies of germplasms. In the Indian sub continent, lentil (Lens culinaris Medik.) is a major rabi pulse crop with 2n = 2x = 14 chromosomes. Chromosomal studies were carried out on Indian lentils during the period of 1952 to 1991 employing orcein squash techniques by different authors but there was no unanimity on chromosome morphology and chromatin length. This is the first study conducted on two wild and 12 cultivated cultivars of Lens for detailed and comparative chromosomal analysis using enzymatic maceration and air drying (EMA) based Giemsa staining methods. Chromosomal analysis revealed chromosomal stability, uniform karyotype formula (3m + 1m (sat) + 2sm + 1st), one pair of interstitial sat in either chromosome number 3 or 4 and interesting variations in total chromatin length (53.6-121.2 μm) in all the studied cultivars. More studies on other species and cultivars along with the application of flurochrome dyes for characterizing apparently similar chromosomes at the cultivar level may be very useful for future crop improvements.

Analysis of CMA-DAPI bands and preparation of fluorescent karyotypes in thirty Indian cultivars of Lens culinaris

“…Considering the nature of nucleolar chromosomes, molecular banding technique has shed light on chromosomal landmarks and possible differences in NORs that were previously found to be similar in Lens (Mehra et al 1986;Jha et al 2015Jha et al , 2017Jha and Halder 2016).The marker nucleolar chromosomes (4 th , along with the 3 rd , 2 nd and 5 th in few cases) have been confirmed with characteristic CMA-DAPI signals, corroborating to our previous report (Jha et al 2017).…”

“…Identification of distinct subgroups have opened further scopes to complement marker assisted analysis of genetic diversity across varied range of Indian cultivars with valuable agronomic traits. Application of fluorochrome banding method has therefore helped to i) break the perception of an overall similar karyotype of cultivated Lentils as observed in Giemsa plates (Jha et al 2015(Jha et al , 2017Jha and Halder 2016) ii) serve as the chromosomal blueprint for cultivar discrimination, ii) statistically represent the status of chromosomal relationships, iii) highlight the uniqueness of certain Indian cultivars by means of unconventional banding pattern, and v) construct a fluorescent karyotype dataset of Indian Lentil cultivars.…”

“…Except for two (Barasat, Micro type Barasat, Macro type, Table 1), all the cultivars of Lentil were obtained from the Indian Institute of Pulse Research (IIPR), Kanpur. Germination of seeds and chromosome processing through enzymatic maceration and air drying (EMA) was carried out as per our earlier protocol (Jha and Yamamoto 2012;Jha et al 2015Jha et al , 2017. For fluorescent staining with DAPI and CMA, we followed our protocol (Jha 2019) with required modifications.…”

“…Cytogenetic studies of Indian Lentils through conventional method failed to provide uniformity on chromosome morphometric parameters (Bhattacharjee 1953;Sharma and Mukhopadhyay 1963;Sinha and Acharia 1972;Naithani and Sarbhoy 1973;Lavania and Lavania 1983;Nandanwar and Narkhede 1991). On the other hand, we have published detailed karyotype analysis of more than thirty L. culinaris cultivars obtained from the Indian Institute of Pulses (Jha et al 2015(Jha et al , 2017Jha and Halder 2016) through EMA based Giemsa staining method. Our results were found to have near similarities with the results obtained by Ladizinsky (1979).…”

Cytotaxonomic characterization of cultivars and accessions of Lens culinaris Medik. (Fabaceae) from Chile and Canada

“…These methods permit evaluation of differences in the number, form, and size of chromosomes, band polymorphisms, and architectural alterations in the presence of secondary restrictions or nuclear organizing regions (NORs; Guerra 2008). General cytotaxonomic studies on L. culinaris have revealed a chromosome number of 2n = 14 (Bhattacharjee 1953;Sinha & Acharia 1972;Balyan et al 2002;Jha et al 2015). The morphology of the chromosomes varies from metacentric, submetacentric, to subtelocentric or acrocentric (Sinha & Acharia 1972;Manara & Manara 1979;Ladizinsky & Muehlbauer 1993;Rehman & Altaf 1994;Balyan et al 2002;Gaffarzadeh-Namazi et al 2007;Jha et al 2015).…”