scholarly journals Genetic variability in salt tolerance during germination of Stylosanthes humilis H.B.K. and association between salt tolerance and isozymes

1997 ◽  
Vol 20 (3) ◽  
pp. 435-441 ◽  
Author(s):  
Maria Bernadete Lovato ◽  
Paulo Sodero Martins

Variation in salt tolerance of six natural populations of Stylosanthes humilis from three ecogeographic regions, Mata (wet tropical climate), Agreste and Sertão (semi-arid tropical climate) of Pernambuco State, Northeast Brazil, was evaluated on germination in 201 mM NaCl. There were significant differences among families of all populations for germination percentage and of five populations (except Tamandaré, from Mata) for germination rate. Populations from semi-arid regions presented high coefficients of genetic variation, those from Agreste being higher than those from Sertão. Populations from Mata showed low coefficients of genetic variation. The coefficients of genotypic determination were high for five populations, except Tamandaré, both for germination percentage ( > or = 0.89) and for germination rate ( > or = 0.79), indicating the possibility of selection for salt tolerance in these populations. An electrophoretic analysis of esterase and peroxidase isozymes was also performed in the six populations, and correlations were estimated between salt tolerance and allelic frequencies. The analysis of salt tolerant and salt sensitive families of populations from Agreste suggested an association of alleles of a peroxidase locus with salt tolerance during germination in the Caruaru population

1994 ◽  
Vol 42 (6) ◽  
pp. 717 ◽  
Author(s):  
MB Lovato ◽  
PS Martins ◽  
Filho JPD Lemos

The germination response to NaCl treatments (0, 67, 134, 201 and 268 mol m-3) was investigated in 6 natural populations of Stylosanthes humilis from 3 ecogeographic regions of Pernambuco State, north-east Brazil. In general, salt tolerance was high, with percentage germination unaltered up to 67 mol m-3 NaCl in 2 populations and unaltered up to 134 mol m-3 NaCl in the remaining 4. The estimated concentration which reduced percentage germination to 50% varied between populations from 200 to 295 mol m-3 NaCl. Salt affected germination rate even more than it did the germination percentage, being altered at 67 mol m-3 NaCl in all populations. The germination rate was reduced to 50% in the range of 131-176 mol m-3 NaCl. There was a significant variation in salt tolerance between these natural populations, and no relation was found between salt tolerance of the populations and the aridity of their provenance.


2022 ◽  
Vol 81 (1) ◽  
Author(s):  
Iskender Tiryaki ◽  
Nuray Isidogru

The objectives of the present study were to determine salt tolerance levels of 12 different common vetch (Vicia sativa L.) cultivars at germination stage in the presence of 250 mM NaCl and to reveal genetic relationships based on gene targeted functional markers (GTFMs) associated with salt tolerance. The results revealed the presence of a significant genetic variation among the cultivars although s alt stress significantly reduced all germination parameters tested. The cultivar Ozveren was the most salt tolerant with 20.1% reduction in final germination percentage compared to control seeds while cultivars Alınoglu, Ayaz and Bakir did not germinate. The maximum delays in germination rate (G50 = 3.78 days) and synchrony (G10-90 = 3.45 days) were obtained from the cultivars Urkmez and Ozveren, respectively. The GTFMs provided a total of 53.1% polymorphism. The primers of MtSOS2 gene gave the highest numbers of alleles per primer pair while the highest polymorphism rate (77.8%) was obtained from the MtP5CS gene. The first three components of principal component analysis explained 57.63% of total variation. This study concluded that the cultivars determined to be salt tolerant and sensitive at germination stage distributed into three main clades determined by UPGMA analysis while the GTFMs associated with salt tolerance successfully determined the genetic relationships of common vetch cultivars.


Agriculture ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 29
Author(s):  
Roberta Calone ◽  
Rabab Sanoubar ◽  
Enrico Noli ◽  
Lorenzo Barbanti

Salicornia europaea, a halophytic species, was investigated to assess its ability to withstand salinity during seed germination, and to identify suitable indices to interpret salt tolerance at this delicate stage. Seed germination indices (germination percentage (GP), germination energy (GE), germination value (GV), coefficient of germination velocity (CVG), germination rate index (GRI), germination peak value (GPV), mean germination time (MGT), and time to 50% germination (T50)) were calculated under increasing salinity (0, 100, 200, 300, 400, and 600 mM NaCl). Principal component analysis (PCA) was used to describe the relationships involving the variables that account for data variance. Two salinity thresholds were identified (100 and 600 mM NaCl) determining significant decreases in all the indices, except for T50 and MGT. In fact, PCA based on generated correlation circle showed significant negative correlations (r close to −1) between salt stress and GP, GE, GRI, PV, GV, and CVG, whereas no correlation was observed with T50 and MGT (r close to zero). Based on this, GP, GE, GRI, PV, GV, and CVG can be considered useful traits to assess salt tolerance during germination in S. europaea, while T50 and MGT, that were not affected by the range of salinity levels investigated, should not be used for this purpose.


2021 ◽  
Vol 12 ◽  
Author(s):  
Muhammad Farooq ◽  
Jae-Ryoung Park ◽  
Yoon-Hee Jang ◽  
Eun-Gyeong Kim ◽  
Kyung-Min Kim

Soil salinity is a major problem in agriculture because high accumulation of Na+ ions in plants causes toxicity that can result in yield reduction. Na+/K+ homeostasis is known to be important for salt tolerance in plants. Na+/K+ homeostasis in rice (Oryza sativa L.) involves nine high-affinity K+ transporter (HKT) encoding Na+-K+ symporter, five OsNHX Na+/H+ antiporters, and OsSOS1 Na+/K+ antiporter genes. In the present study, we investigated various molecular and physiological processes to evaluate germination rate, growth pattern, ion content, and expression of OsHKT, OsNHX, and OsSOS1genes related to Na+/K+ homeostasis in different rice genotypes under salt stress. We found a significant increase in the germination percentage, plant vigor, Na+/K+ ratio, and gene expression of the OsHKT family in both the roots and shoots of the Nagdong cultivar and salt-tolerant cultivar Pokkali. In the roots of Cheongcheong and IR28 cultivars, Na+ ion concentrations were found to be higher than K+ ion concentrations. Similarly, high expression levels of OsHKT1, OsHKT3, and OsHKT6 were observed in Cheongcheong, whereas expression levels of OsHKT9 was high in IR28. The expression patterns of OsNHX and OsSOS1 and regulation of other micronutrients differed in the roots and shoots regions of rice and were generally increased by salt stress. The OsNHX family was also expressed at high levels in the roots of Nagdong and in the roots and shoots of Pokkali; in contrast, comparatively low expression levels were observed in the roots and shoots of Cheongcheong and IR28 (with the exception of high OsNHX1 expression in the roots of IR28). Furthermore, the OsSOS1 gene was highly expressed in the roots of Nagdong and shoots of Cheongcheong. We also observed that salt stress decreases chlorophyll content in IR28 and Pokkali but not in Cheongcheong and Nagdong. This study suggests that under salt stress, cultivar Nagdong has more salt-tolerance than cultivar Cheongcheong.


2018 ◽  
Vol 51 (3) ◽  
pp. 51-68 ◽  
Author(s):  
M.K. Hasan ◽  
M.S. Islam ◽  
M.R. Islam ◽  
H.N. Ismaan ◽  
A. El Sabagh

Abstract A laboratory experiment regarding germination and seedling growth test was conducted with three black gram genotypes tested under three salinity levels (0, 75 and 150 mM), for 10 days, in sand culture within small plastic pot, to investigate the germination and seedling growth characteristics. Different germination traits of all black gram genotypes, like germination percentage (GP), germination rate (GR), coefficient of velocity of germination (CVG) greatly reduced, as well as mean germination time (MGT) increased with increasing salt stress. At high salt stress, BARI Mash-3 provided the highest GP reduction (28.58%), while the lowest was recorded (15.79% to control) in BARI Mash-1. Salinity have the negative impact on shoot and root lengths, fresh and dry weights. The highest (50.32% to control) and lowest reduction (36.39%) of shoot length were recorded in BARI Mash-2 and BARI Mash-1, respectively, under 150 mM NaCl saline conditions. There were significant reduction of root lengths, root fresh and dry weight, shoot length, shoot fresh and dry weight in all genotypes under saline condition. The genotypes were arranged as BARI Mash-1 > BARI Mash-3 > BARI Mash-2, with respect to salinity tolerance.


Genetics ◽  
1975 ◽  
Vol 80 (4) ◽  
pp. 785-805
Author(s):  
P T Spieth

ABSTRACT Electrophoretically detectable variation in the fungus Neurospora intermedia has been surveyed among isolates from natural populations in Malaya, Papua, Australia and Florida. The principal result is a pattern of genetic variation within and between populations that is qualitatively no different than the well documented patterns for Drosophila and humans. In particular, there is a high level of genetic variation, the majority of which occurs at the level of local populations. Evidence is presented which argues that N. intermedia has a population structure analogous to that of an annual vascular plant with a high level of vegetative reproduction. Sexual reproduction appears to be a regular feature in the biology of the species. Substantial heterokaryon function seems unlikely in natural populations of N. intermedia. Theoretical considerations concerning the mechanisms underlying the observed pattern of variation most likely should be consistent with haploid selection theory. The implications of this constraint upon the theory are discussed in detail, leading to the presentation of a model based upon the concept of environmental heterogeneity. The essence of the model, which is equally applicable to haploid and diploid situations, is a shifting distribution of multiple adaptive niches among local populations such that a given population has a small net selective pressure in favor of one allele or another, depending upon its particular distribution of niches. Gene flow among neighboring populations with differing net selective pressures is postulated as the principal factor underlying intrapopulational allozyme variation.


Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1487-1493 ◽  
Author(s):  
Andrew G Clark ◽  
David J Begun

Abstract Differential success of sperm is likely to be an important component of fitness. Extensive variation among male genotypes in competitive success of sperm in multiply mated females has been documented for Drosophila melanogaster. However, virtually all previous studies considered the female to be a passive vessel. Nevertheless, under certain conditions female fitness could be determined by her role in mediating use of sperm from multiple males. Here we ask whether females differ among genotypes in their tendency to exhibit last-male precedence. Competition of sperm from two tester male genotypes (bwD and B3-09, a third-chromosome isogenic line from Beltsville, MD) was quantified by doubly mating female lines that had been rendered homozygous for X, second, or third chromosomes isolated from natural populations. The composite sperm displacement parameter, P2′, was highly heterogeneous among lines, whether or not viability effects were compensated, implying the presence of polymorphic genes affecting access of sperm to eggs. Genetic variation of this type is completely neutral in the absence of pleiotropy or interaction between variation in the two sexes.


2021 ◽  
pp. 1-9
Author(s):  
Ashwini P. Benke ◽  
Ram Krishna ◽  
Roshni R. Samarth ◽  
Shweta S. Dhumal ◽  
Waquar A. Ansari ◽  
...  

Abstract Acquisition and germination of seeds are the most desired targets for the improvement of vegetatively propagated crops. In the present study, we developed a potential embryo germination protocol for the Red Globe grape cultivar having a low seed germination rate. Three grape berries at different developmental stages, viz. 50, 60 and 70 days after flowering (DAF), were selected for in-vitro embryo germination. Three growth media, namely Emershad and Ramming (ER), Nitsch and Nitsch (NN) and Murashige and Skoog (MS), and plant growth regulators (benzyl amino purine (BA), 0.5, 0.7 and 0.9 mg/l; indole butyric acid (IBA), 1.0, 1.5 and 2.0 mg/l; and gibberellic acid (GA), 0.1, 0.3 and 0.9 mg/l) were screened individually in different combinations with three amino acids, namely cysteine, glutamine and proline (2.0 μmol/l each). The maximum embryos germination percentage recorded at 70 DAF was 63.33, 47.78 and 45.56% in ER, NN and MS media, respectively, supplemented with 0.9 mg/l BA, 2.0 mg/l IBA, 0.9 mg/l GA and 2.0 μmol glutamine. Glutamine was found to have the most significant impact, and it improved the rescued embryos germination. The present study provides a potential recipe for a medium that can facilitate efficient germination of grape embryos.


Sign in / Sign up

Export Citation Format

Share Document