Twenty-five microsatellite markers (Table 1) distributing all twelve rice chromosomes were utilized to access genetic diversity among 48 putative EMS mutants of super basmati (Table 3). Similar number of microsatellite markers previously used as marker set for genetic analysis of rice (Pal et al. 2004; Rahman et al. 2010; Kumar and Bhagwat 2012; Allhgholipour et al. 2014).
Table 3
Identification of super basmati mutants based upon absence or presence of unique bands on chromosomes at particular base pairs
Super basmati | M.N | RM 110 | RM 161 | RM 242 | RM 277 | RM 287 | RM 72 | RM103 | RM105 | RM5 | RM 252 | RM 1 | RM 154 | RM152 | RM 222 | RM 44 | RM257 | RM174 | RM124 | RM171 | RM229 | RM271 | RM334 | RM 487 | RM70 | RM235 |
B.P | 80; 300 | 150 | 200;225 | 100;125 | 100;125 | 200; 225 | 425 | 250;300 | 225;250 | 250 | 75; 100; 200; 300 | 200;425 450;550 1000 | 150;250 | 100; 200; 300 | 150;175; 200;250; 275;400; 500 | 200; 250 | 200; 250 | 225;250 | 100;150 | 100;125 | 100;125 | 100;150 | 150;200;250 | 130;160 | 125 |
C.D | C.N | 2 | 5 | 9 | 12 | 11 | 8 | 6 | 9 | 1 | 4 | 1 | 2 | 8 | 10 | 8 | 9 | 2 | 4 | 10 | 11 | 10 | 5 | 3 | 7 | 12 |
0.25 | M48 | A | A````````: | A | A | A | A | A | A | A | A | A | P | A | A | P | A | P | A | A | A | A | A | A | A | A |
M105 | A | A | A | A | A | A | A | A | A | A | A | P | A | A | P | P | A | A | A | A | A | A | A | A | A |
M43 | A | A | A | A | A | A | A | A | A | A | P | P | P | A | P | A | P | A | A | A | P | P | P | A | A |
M88 | A | P | A | A | A | A | A | A | A | A | P | P | A | A | P | A | A | A | A | A | P | A | P | A | A |
M56 | A | P | A | A | A | A | A | A | A | A | P | P | P | A | P | P | A | A | A | P | P | A | P | A | A |
M116 | A | P | A | P | A | A | A | P | A | A | P | A | A | A | P | P | A | A | P | P | P | P | A | A | A |
M96 | A | P | A | P | A | A | A | A | A | A | P | P | P | P | P | P | P | A | A | A | A | P | A | A | A |
M109 | A | A | A | P | A | A | A | P | A | A | P | P | P | P | P | P | P | A | A | A | A | P | A | A | P |
M114 | A | A | A | P | A | A | A | A | A | A | P | A | P | A | P | A | 10 | P | A | A | A | A | A | A | P |
M118 | A | A | A | P | A | A | A | A | A | A | P | P | A | A | P | A | A | P | A | A | P | A | A | A | P |
M100 | A | A | A | P | A | A | P | A | A | A | P | P | P | A | P | P | A | A | A | A | P | A | A | A | P |
M101 | A | A | A | A | A | A | A | A | A | A | P | P | A | A | P | A | P | A | A | A | P | P | A | A | P |
0.5 | M104 | A | A | A | P | A | A | A | A | A | A | P | P | P | A | P | A | A | A | A | A | A | A | A | A | P |
M45 | A | A | A | A | A | A | A | A | A | A | P | P | P | A | P | A | P | A | A | A | A | A | A | A | P |
M117 | P | A | A | A | A | A | A | A | A | A | P | P | A | A | P | A | A | P | P | A | A | A | A | A | P |
M32 | A | A | A | A | A | A | A | A | A | A | P | P | P | A | P | A | A | P | A | A | P | A | P | A | A |
M35 | A | P | A | P | A | A | A | A | A | A | A | A | P | P | P | P | A | A | A | A | P | A | A | A | A |
M42 | A | A | A | P | A | A | A | P | A | A | P | A | P | P | P | P | A | A | A | P | P | A | A | A | A |
M51 | A | A | A | P | A | A | A | A | A | P | P | P | P | P | P | P | A | A | P | P | P | A | A | A | A |
M115 | A | A | A | P | A | A | A | P | A | A | A | P | P | A | P | P | A | A | A | P | P | A | A | A | A |
M121 | A | A | A | A | A | A | A | P | A | A | A | P | P | A | P | P | A | A | A | P | P | A | A | A | A |
M34 | A | P | A | A | A | A | A | A | A | P | P | A | A | A | P | P | A | P | A | P | A | A | A | A | A |
M124 | A | P | A | A | A | A | A | A | A | A | P | P | A | A | P | P | P | A | P | A | A | P | A | A | P |
0.75 | M63 | A | P | A | A | A | A | A | A | A | A | P | A | A | A | P | P | P | P | A | A | P | P | A | A | P |
M95 | A | A | A | A | A | A | A | A | A | P | P | P | A | A | P | P | P | A | A | A | P | P | A | A | P |
M38 | A | A | A | A | A | A | A | A | A | A | P | P | A | A | P | A | P | A | A | A | A | A | A | A | P |
M22 | P | A | A | P | A | A | A | A | A | A | P | P | P | P | P | A | A | A | P | A | A | P | P | A | P |
M73 | P | A | A | P | A | A | A | A | A | A | A | P | P | A | P | A | A | P | P | A | A | P | P | A | P |
M70 | P | A | A | P | A | A | A | A | P | A | P | P | A | A | P | P | A | A | P | P | A | P | A | A | A |
M93 | P | A | A | P | A | A | A | A | P | A | A | P | A | A | P | A | A | P | A | P | A | A | A | P | A |
M21 | P | A | A | P | A | A | A | A | P | A | P | P | P | A | P | A | A | A | P | A | A | A | A | A | A |
M60 | P | A | A | A | A | A | A | A | P | A | P | P | P | A | P | A | A | A | A | A | A | A | P | A | P |
M52 | P | A | A | A | A | A | A | A | P | A | P | P | P | A | P | A | A | A | A | A | A | A | A | A | P |
M61 | P | A | A | A | A | A | A | A | P | A | P | P | P | A | P | A | P | A | A | A | A | A | A | A | P |
1 | M24 | P | A | A | A | A | A | A | A | P | A | P | P | A | A | P | A | A | P | A | A | A | P | A | A | P |
M125 | P | P | A | A | A | A | A | A | A | A | P | P | A | A | P | A | P | A | P | A | P | P | P | A | A |
M17 | P | A | A | P | A | A | A | A | P | A | P | P | A | P | P | A | P | A | A | A | P | A | A | A | A |
M92 | P | A | A | P | P | A | A | A | A | P | P | P | A | P | P | A | A | A | P | A | A | A | P | A | A |
1.25 | M123 | P | A | A | A | A | A | A | A | A | P | P | P | A | A | P | A | A | P | P | A | A | P | P | A | A |
M12 | P | P | A | A | A | A | A | A | A | P | A | P | A | A | P | A | A | A | P | A | A | A | A | A | A |
M25 | P | P | A | A | A | A | A | A | A | A | A | P | A | A | P | A | A | P | P | A | P | A | A | A | A |
M78 | A | A | A | A | A | A | A | A | A | A | P | P | A | A | P | A | P | A | A | A | A | A | A | P | A |
M129 | P | A | A | A | A | A | A | A | A | A | P | P | A | A | P | A | A | A | A | A | A | A | P | A | A |
M3 | A | A | P | A | A | P | A | P | A | A | A | P | P | A | P | A | P | A | A | A | P | A | P | A | A |
1.5 | M71 | P | A | A | A | A | A | A | A | A | A | A | P | P | A | P | A | A | A | A | A | A | P | A | A | A |
M72 | P | A | A | A | A | A | A | A | P | A | P | P | A | A | P | A | A | A | P | A | A | P | P | A | A |
M65 | P | A | A | A | A | A | A | A | P | P | P | P | A | P | P | A | A | A | A | A | A | P | A | A | A |
C.D: Chemical Doses; M.N: Markers Name; B.P: Base pairs; A: Absence of unique bands; P: Presence of unique bands |
A broad range of genetic variability was discovered among different mutants of super basmati for 23 SSR markers (Table 2). The remaining two markers (RM5 and RM103) were monomorphic (Table 2). A sum of 91 alleles was identified of which nine alleles (9.89%) were considered as monomorphic and remaining 82 alleles (90.10%) were established to be polymorphic with average of 85.6 bands per primer (Table 2). Seventeen SSR primers produced 100 polymorphic bands. The level of polymorphism was calculated by the PIC value of each marker loci. The PIC value differed from locus to locus and ranged from 0.04 (RM5) to 0.88 (RM44) with the average of 0.44 for each locus (Table 2). The highest PIC value was examined in RM44 (0.88) followed by RM154 (0.87), RM1 (0.79), RM252 (0.71), RM334 (0.64), RM487 (0.63), RM110 (0.59) and RM257 (0.59) based upon SSRs data of mutant genotypes (Table 2). PIC value is a mirror of allelic variability among and within varieties which was not always higher for every tested SSRs loci (Kumar et al. 2012; Kumar and Bhagwat 2012; Allhgholipour et al. 2014). It has been reported by (Yesmin et al. 2014) that the higher PIC value of marker designated the higher polymorphism which helped to select best marker in phylogenic analysis. According to report of (Rahman et al. 2010; Allhgholipour et al. 2014), low PIC value may be the product of closely related genotypes as well as the high PIC value might be the effect of diverse genotypes. The high PIC values suggested that microsatellites were polymorphic and suitable to detect the genetic variation in rice cultivar at DNA level. Markers were categorized as informative when PIC value was greater than 0.5 (Taheri et al. 2016; Kumar et al. 2012). The range of PIC value was in series of PIC value of existing outcome (Jain et al. 2004; Thomson et al. 2009; Pervaiz et al. 2010; Matin et al. 2012). The PIC value for all SSRs loci ranged from 0.36–0.98 in rice genotypes according to Kumar et al. (2010) reported that eight SSRs primers produced 100% polymorphic bands from total of 20 SSRs primers. According to (Kumar and Bhagwat 2012), all SSRs primer were distributed overall 12 chromosome of rice were found to be polymorphic with PIC range of 0.125 (RM208) and 0.68 (RM1) across 20 dwarf, semi dwarf mutant and wild (WL112) of rice variety. Mean value of alleles (3.29) and PIC (0.47) were comparable to the finding of current study. The present PIC range is also comparable with that previously reported by Patel et al. (2014) with value of 0.36–0.78 among colored and white rice genotypes. They also reported that nine SSRs marker were found to be polymorphic from 14 SSRs markers with 129 bands. According to study of Sahu et al. (2017) 83 loci (24.02%) revealed polymorphism out of 343 loci between rice genotypes. Microsatellites have 28.98% (51) polymorphic ratio. The highest polymorphism about 41.67% was occurred on second chromosome as well as twelve chromosome numbers had lowest polymorphic % age of 6.67. The PIC range of the recent conclusion was lower than previous observation reported in rice (Jain et al. 2003) and higher then (Singh et al. 2004; Johsi and Behera 2006; Xu et al. 2004; Brondani et al. 2006; Rahman et al. 2008; Rahman et al. 2010) respectively due to different selected SSRs markers as well as diverse genotypes of rice.
Table 2
Genetic polymorphism revealed by SSRs (PCR) analysis among genotypes of super basmati
S.N | M* | C.N* | P.R* | MAF* | A.N* | TNAP* | TNL* | TNPA* | TNMA* | P (%)* | G.D* | H* | PIC* |
1 | RM110 | 2 | 80–300 | 1.36 | 4 | 62 | 2 | 4 | 0 | 100 | 0.7408 | 1.24 | 0.586 |
2 | RM161 | 5 | 150–180 | 0.89 | 2 | 85 | 1 | 2 | 0 | 100 | 0.1958 | 0.22 | 0.1766 |
3 | RM242 | 9 | 200–225 | 0.51 | 2 | 48 | 1 | 2 | 0 | 100 | 0.4998 | 0.98 | 0.3749 |
4 | RM277 | 12 | 125–150 | 0.67 | 2 | 65 | 1 | 2 | 0 | 100 | 0.4422 | 0.66 | 0.3444 |
5 | RM287 | 11 | 100–125 | 0.5 | 2 | 49 | 1 | 1 | 1 | 50 | 0.5 | 1 | 0.375 |
6 | RM72 | 8 | 200–225 | 0.5 | 2 | 49 | 1 | 1 | 1 | 50 | 0.5 | 1 | 0.375 |
7 | RM105 | 9 | 90–200 | 1.9 | 4 | 95 | 2 | 2 | 2 | 50 | 0.18 | 0.09 | 0.1638 |
8 | RM5 | 1 | 94–250 | 1.98 | 4 | 110 | 2 | 4 | 0 | 100 | 0.0396 | 0.04 | 0.0392 |
9 | RM252 | 4 | 75–300 | 2.3 | 6 | 96 | 3 | 6 | 0 | 100 | 0.8764 | 1 | 0.7075 |
10 | RM1 | 1 | 75–600 | 2.42 | 6 | 72 | 3 | 6 | 0 | 100 | 0.934 | 0.68 | 0.7879 |
11 | RM154 | 2 | 175–1000 | 3.39 | 8 | 112 | 3 | 8 | 0 | 100 | 1.005 | 0.94 | 0.8641 |
12 | RM44 | 8 | 80–900 | 4.42 | 10 | 270 | 5 | 10 | 0 | 100 | 0.9964 | 0.12 | 0.8781 |
13 | RM222 | 10 | 140–275 | 1.42 | 4 | 64 | 3 | 4 | 0 | 100 | 0.756 | 0.96 | 0.6012 |
14 | RM152 | 8 | 80–700 | 2.4 | 4 | 68 | 2 | 4 | 0 | 100 | 0.7244 | 0.96 | 0.5747 |
15 | RM257 | 9 | 150–500 | 1.4 | 4 | 149 | 2 | 4 | 0 | 100 | 0.7376 | 1.16 | 0.5852 |
16 | RM174 | 2 | 200–300 | 1.65 | 3 | 66 | 1 | 2 | 1 | 66.66 | 0.455 | 0.7 | 0.3515 |
17 | RM124 | 4 | 250–275 | 1.46 | 4 | 63 | 1 | 4 | 0 | 100 | 0.5948 | 0.96 | 0.4654 |
18 | RM171 | 10 | 300–400 | 0.82 | 2 | 54 | 1 | 2 | 0 | 100 | 0.2952 | 0.2 | 0.2516 |
19 | RM229 | 11 | 100–125 | 0.91 | 2 | 78 | 1 | 2 | 0 | 100 | 0.1638 | 0.18 | 0.1504 |
20 | RM271 | 10 | 100–125 | 0.78 | 2 | 87 | 1 | 2 | 0 | 100 | 0.3432 | 0.32 | 0.2843 |
21 | RM334 | 5 | 100–200 | 1.33 | 4 | 74 | 2 | 3 | 1 | 75 | 0.807 | 1.26 | 0.635 |
22 | RM487 | 3 | 150–300 | 1.43 | 4 | 129 | 2 | 3 | 1 | 75 | 0.779 | 0.9 | 0.6206 |
23 | RM70 | 7 | 130–160 | 0.5 | 2 | 79 | 1 | 1 | 1 | 50 | 0.5 | 1 | 0.375 |
24 | RM103 | 6 | 240–425 | 0.96 | 2 | 50 | 1 | 1 | 1 | 50 | 0.0768 | 0.08 | 0.0739 |
25 | RM235 | 12 | 100–132 | 0.68 | 2 | 66 | 1 | 2 | 0 | 100 | 0.4352 | 0.64 | 0.3405 |
Total | 36.58 | 91 | 2140 | 44 | 82 | 9 | 2166.66 | 13.578 | 17.29 | 10.982 |
Mean | 1.4632 | 3.64 | 85.6 | 1.76 | 3.28 | 0.36 | 86.66 | 0.5431 | 0.691 | 0.439 |
M*: Markers; C.N*: Chromosome Number; P.R*: Product range; MAF*: Major allele Frequency; A.N*: Allele Number; TNAP*: Total number of allele in population; TNL*: Total number of loci; TNPA*: Total number of polymorphic allele; TNMA*: Total number of Monomorphic allele; P*: Polymorphism %; G.D*: Genetic Diversity; H*: Heterzygosity; PIC*: Polymorphism Information Content |
PIC value showed positive signification correlation with allele numbers in current study. The maximum numbers of alleles was ten in RM44 marker with the highest PIC value of 0.88. Markers (RM161, RM242, RM277, RM287, RM72, RM171, RM229, RM271, RM70, RM103 and RM235) have minimum two numbers of alleles (Table 2) with mean value of 3.64 alleles/locus. The overall amplified product range was from 75 bp (RM1; RM252) to 1000 bp (RM154). SSR markers demonstrated many bands that common among mutants and wild of super basmati. Correlation of allele number and their PIC value might also depends upon repeat number and repetitive sequence of microsatellites (Yu et al. 2003; Temnykh et al. 2000; Temnykh et al. 2001; Ni et al. 2002). The present range and mean value of allele numbers were similar to those reported by (Pal et al. 2004) among basmati and non-basmatic rice varieties. They proposed that range of alleles was 1–8 with mean value of 3.51 alleles/locus. RM252 marker showed the high PIC value (0.8) with the maximum eight allele numbers. The mean PIC vale for all SSRs loci was 0.4 that were similar to the current findings in rice. According to conclusion of (Rahman et al. 2008), marker (RM1 and RM334) were found to be polymorphic among rice varieties of Bangladesh with the PIC value of 0.862 and 0.863 respectively.
Interestingly, several mutant loci exhibited presence or absence of discrete bands by different set of SSR markers (Table 3). These unique alleles were not produced in wild used. Every mutant genotypes distinguished from each other either alone or combined set of SSR primers. Genotypic variations were existed in putative mutants at a particular base pair of definite chromosomes (Table 3) because the selected primers sequence located from particular chromosomes. These genetic modifications occurred either in the form of discrete alleles or non-amplified PCR product due to mutation in primer sequence. For instance, phenotypic putative mutants (xantha and albino; M56) (Fig. 1) showed genetic changes in various microsatellites with respect to particular base pair such as RM161 (150 bp), RM1 (75 bp; 100 bp; 200 bp; 300 bp), RM152 (150 bp; 250 bp), RM44 (150 bp; 175 bp; 200 bp; 250 bp; 275 bp; 400 bp and 500 bp), RM257 (200 bp; 250 bp), RM229 (100–125 bp), RM271(100–125 bp) and RM487(150 bp; 200 bp; 250 bp) on 5, 1, 8, 8, 9, 11, 10 and 3 chromosome of rice respectively (Table 3). Correspondingly, microsatellites (RM110, RM154, RM152; RM44 and RM334) showed molecular variations on chromosome 2, 2, 8, 8 and 5 with range of 75-1000 bp (Table 3) in viridis and albino mutants (M71) of super basmati respectively (Fig. 1). The current outcomes pointed out that wild and mutants were genetically dissimilar to each other. A major purpose of molecular analysis is to sort out a marker which can discriminate a desired genotype from control and rest of other genotypes used. Kumar and Bhagwat (2012) described that distinct alleles were identified for 18 rice mutants either in a single or combination of two SSRs markers. A sum of 19 unique alleles was detected from 17 genotypes of weedy rice with the size range of 200 to1300bp (Choudhary et al. 2011). Results of Gealy et al. (2009) explained that presence or absence of discrete SSRs loci was exploited to differentiate white rice from US weedy rice. According to Yu et al. (2005), gene flow was caused by existing of unique bands in weedy rice. It was also reported that regular occurrence of gene flow from domesticated to weedy rice was happened due to presence of discrete alleles (Chen et al. 2004). Ethyl methane sulphonate (EMS) has been reported to be the most potent in producing chlorophyll mutation among chemical mutagens in rice (Kawai and Sato 1965) and other crops (Jacob 1965). Chlorophyll mutation were group into three classes including albino (white), xantha (yellow), viridis (light green) (Cheema and Atta 2003). Detectable mutation is valuable in mutant populations as clue of variability (Wu et al. 2005).
In the current study, putative mutants that decreased or increased in their agronomic features showed less or more in the similar cluster (Fig. 2). Dendrogram divided into four main clusters with sub-clustering. Cluster one, two, three and four has 2, 38, 2, 6 genotypes of super basmati respectively (Fig. 2). Phylogenic study exposed a pair-wise similarity ranging from 40% (M45 and M116) to 96% (M105 and W1) at chemical dose of (0.25% and 0.5%) and (0.25% and 0%) respectively (Fig. 2). Previous finding of (Kumar et al. 2010) also supported the present study that similarity coefficient varied from 0.40–0.96 among genotypes of rice. Similarity index varied from 0.56–0.95 among red and white rice genotypes for SSRs markers that described by (Patel et al. 2014). According to finding of (Kumar and Bhagat 2012), similarity index was 35% as establishment of genetic diversity among dwarf mutant genotypes. It was also reported by (Herrera et al. 2008) that mean similarity was 0.48 among eighteen genotypes of all SSRs loci using microsatellite markers. Results of (Naeem et al. 2015) revealed a pair wise similarity range from 0.39–0.89 was observed after mutation in rice varieties. The recent results are in synchronization with those of (Arif et al. 2005) who examined an increase or decrease in genetic diversity of mutated genotypes as compared to their control genotypes. Jaccard’s genetic similarity ranged from 0.04–0.92 according to (Tu et al. 2007; Wong et al. 2009). According to finding of (Pal et al. 2004), genetic relationship among 13 basmati and non-basmati rice varieties demonstrated that these genotypes similar to each other by 0.65–0.94 pair-wise similarity index. The high degree of diversity was observed among rice cultivar with 21–86% similarity that previously reported by (Matin et al. 2012). According to statement of (Oladosu et al. 2015; Tu et al. 2007; Wong et al. 2009), difference between the highest and lowest value of similarity coefficient indicated a high level of genetic diversity among rice genotypes depend upon different set of SSRs markers and diverse selection of rice genotypes. The high genetic diversity was observed in dendrogram coefficient among mutant rice varieties due to effect of induced mutation (Oladosu et al. 2015).
It was also suggested from current study that more diverse mutants existed using high EMS doses. Phenotypic and genotypic data correlated to each other indicating that EMS might be brought desired genetic variability in putative mutants of super basmati. These genetic changes might be useful in selection of desired mutant genotype of rice in future. According to (Babaei et al. 2010; Domingo et al. 2007; Oladosu et al. 2015), induced genetic variability was verified through phenotypic and genetic study of quantitative traits in rice. Moreover, results of (Elayaraja et al. 2005; Luzi-Kihupi et al. 2008) showed that induced mutation could produce a significant quantity of genetic changes for development as well as diversification of crop. These genetic changes might also be helpful in improvement of mutant lines with improved traits, which are deficient in wild (Shehata et al. 2009).