Assessment of the genetic variability amongst mandarin (Citrus reticulata Blanco) accessions in Bhutan using AFLP markers

Abstract

BackgroundBhutan is a small Himalayan country lying within the region considered to be the origin of citrus. Diverse citrus wild types grow naturally in different climates, elevations and edaphic conditions, but only mandarin is cultivated commercially. The first report of Huanglongbing (also known as greening disease) in Bhutan in 2003, and the threat it posed to the country’s citrus orchards prompted the collection of mandarin germplasm from across the country. This paper describes the genetic diversity of mandarin accessions in Bhutan using amplified fragment length polymorphic (AFLP) markers.ResultsTwenty three accessions of Bhutanese mandarin were analyzed using AFLP markers to assess the genetic variability that is believed to exist only in Bhutan and some parts of North East India and South China. Five primer pairs (E-ACA/M-CAG, E-ACG/M-CAT, E-ACC/M-CTT, E-AAG/M-CAA and E-ACA/M-CTC) were identified (based on the number and quality of polymorphic bands produced) and used for the analyses. A total of 244 bands were scored visually of which 126 (52%) were polymorphic with an average polymorphism information content of 0.95 per marker. A cluster dendrogram based on multiscale bootstrap sampling categorized twenty three accessions into two broad groups containing eight and 14 accessions, respectively. Group A consisted accessions (Tsirang1, Tsirang3, Sarpang1, Dagana4, Samtse4, Dagana1, and Trongsa2) from five districts (Tsirang, Sarpang, Samtse, Dagana and Trongsa) and their grouping was strongly supported by bootstrap analysis (B p-value = 96%, AU p-value = 86%). Cluster B consisted of 14 accessions divided into three sub-groups (1, 2 and 3). However, bootstrap value supported significantly for subgroup1 (containing accessions: Tsirang4, Sarpang5, and Tsirang2) and subgroup3 (with accessions - Zhemgang2, Zhemgang3 and Zhemgang4).ConclusionThis study indicates that Bhutanese mandarin germplasm collected from across the country are genetically diverse although the level of variability differed among the accessions assessed. The variation in genetic variability was observed irrespective of where the accessions were collected suggesting that phenotype and geographical location can serve a basis for future germplasm collection in Bhutan. Further, five primer pair combinations could separate 23 mandarins accessions considered in this study, suggesting that AFLP markers can be a useful tool for future identification.

Evaluation of a New Thornless Strain of Mexican Lime (Citrus aurantifolia, Swingle) Under Kaferelsheikh Governorate Conditions, Egypt

“…The highest flower pedicel length 0.33 and 0.35 cm observed with the new strain while the lowest length of flower pedicel 0.247 and 0.270 cm obtained with local Mexican lime in both seasons. Also, the highest stamen number obtained by new strain lime which ranges from 22.0 to 21.75 compared with local Mexican lime which ranges from 18.5 to19.5 .The abovementioned results are in agreement with the results obtained by El-Barkouky and Khalil (1993) on lime, Dorji and Yapwattanaphun (2011). and Kinley and Chinawat (2011)on mandarin trees.…”

AFLP Fingerprinting Analysis of Citrus Cultivars and Wild Accessions from Oman Suggests the Presence of Six Distinct Cultivars

“…Previous studies have shown that populations with limited outcrossing tend to having a low level of genetic diversity and a moderate to high level of genetic differentiation (Al-Sadi et al 2012;Al-Maamari et al 2014;Gannibal et al 2014;Al-Sadi et al 2015). However, it has been reported that there was a range of polymorphism (41-70%) in mandarin analyzed by AFLP which suggested the possibility of having diverse type of mandarins within the accessions examined (Dorji & Yapwattanaphun 2015). Genetic variation and their relatedness studied in pummelo cultivars with AFLP markers indicated that the similarity was high in samples even collected from different locations.…”

“…The AFLP markers are described as a strong molecular apparatus extensively exercised in genetic mapping, population genetics, phylogenetics or plant cultivar documentation. The AFLP procedure is extremely steady and has the capacity of reproducibility without depending on earlier sequence information (Liang et al 2007;Al-Sadi et al 2012;Dorji & Yapwattanaphun 2015). It has been used in phylogenetic studies of citrus and related genera (Chao et al 2005;Althoff et al 2007;Pang et al 2007;Dorji & Yapwattanaphun 2015).…”

“…The AFLP procedure is extremely steady and has the capacity of reproducibility without depending on earlier sequence information (Liang et al 2007;Al-Sadi et al 2012;Dorji & Yapwattanaphun 2015). It has been used in phylogenetic studies of citrus and related genera (Chao et al 2005;Althoff et al 2007;Pang et al 2007;Dorji & Yapwattanaphun 2015). Therefore, the procedural and reproducibility advantage of AFLP marker in citrus and other related crops have made it a useful technique to study the genetic variability and cultivars description.…”

Molecular genetic diversity assessment of Citrus species grown in Iran revealed by SSR, ISSR and CAPS molecular markers

“…(Palmer et al, 1988;Bayer et al, 2009;Lu et al, 2011). More recently, different molecular markers such as cleaved amplified polymorphic sequence (CAPS) of cpDNA (Yamamoto et al, 2013;Ninomiya et al, 2015;Fujii et al, 2016) (Nonaka et al, 2017;Dorji and Yapwattanaphun, 2015;Froelicher et al, 2011), have been used for identification, parentage analysis and phylogeny of citrus species or cultivars.…”