scholarly journals Recurrent Selection for Improved Germination under Water Stress in Russian Dandelion

2017 ◽  
Vol 142 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Katrina J.M. Hodgson-Kratky ◽  
Olivier M. Stoffyn ◽  
David J. Wolyn

Russian dandelion [Taraxacum kok-saghyz (TKS)] is a promising candidate for introducing natural rubber production into North America. Seeds normally germinate in a humid microenvironment, such as the thatch layer of a lawn or under a canopy of grass; however, 5% to 15% establishment is often observed on bare soil, presumably due to water stress. Phenotypic selection and half-sib family recurrent selection were conducted for three cycles to improve germination in vitro, under low osmotic potential (Ψs), using a polyethylene glycol (PEG) solution. Populations were then tested for establishment on bare soil in the greenhouse and field. Germination under water stress in vitro increased from 5.8% for the cycle 0 (C0) population to 40.8% and 47.8% for the C3-phenotypic and C3-half-sib family populations, respectively. Soil establishment in the greenhouse and field was improved up to two- and 4-fold, respectively, compared with the C0, in two of four greenhouse experiments and three of eight field experiments. Overall, recurrent selection for germination under water stress in vitro has potential to improve establishment in the field and can be incorporated into current breeding programs to support the overall goal of creating cultivars with high-rubber yield.

2011 ◽  
Vol 11 (spe) ◽  
pp. 50-55 ◽  
Author(s):  
Ivan Schuster

Although thousands of scientific articles have been published on the subject of marker-assisted selection (MAS) and quantitative trait loci (QTL), the application of MAS for QTL in plant breeding has been restricted. Among the main causes for this limited use are the low accuracy of QTL mapping and the high costs of genotyping thousands of plants with tens or hundreds of molecular markers in routine breeding programs. Recently, new large-scale genotyping technologies have resulted in a cost reduction. Nevertheless, the MAS for QTL has so far been limited to selection programs using several generations per year, where phenotypic selection cannot be performed in all generations, mainly in recurrent selection programs. Methods of MAS for QTL in breeding programs using self-pollination have been developed.


2006 ◽  
Vol 54 (3) ◽  
pp. 351-358 ◽  
Author(s):  
P. Pepó

Plant regeneration via tissue culture is becoming increasingly more common in monocots such as maize (Zea mays L.). Pollen (gametophytic) selection for resistance to aflatoxin in maize can greatly facilitate recurrent selection and the screening of germplasm for resistance at much less cost and in a shorter time than field testing. In vivo and in vitro techniques have been integrated in maize breeding programmes to obtain desirable agronomic attributes, enhance the genes responsible for them and speed up the breeding process. The efficiency of anther and tissue cultures in maize and wheat has reached the stage where they can be used in breeding programmes to some extent and many new cultivars produced by genetic manipulation have now reached the market.


2002 ◽  
pp. 25-30
Author(s):  
Pál Pepó ◽  
Szilárd Tóth

Genetic manipulation may not replace any conventional method in crop breeding programs, but it can be an important adjunct to them. Plant regeneration via tissue culture is becoming increasingly more common in monocots such as corn (Zea mays L.). In vitro culturability and regeneration ability of corn decreased as homozigosity increased, which suggested that these two attributes were controlled primarily by dominant gene action. Pollen (gametophytic) selection for resistance to aflatoxin in corn can greatly facilitate recurrent selection and screening of germplasm for resistance at a much less cost and shorter time than field testing. Integration of in vivo and in vitro techniques in maize breeding program has been developed to obtain desirable agronomic attributes, speed up the breeding process and enhance the genes responsible for them. The efficiency of anther and tissue cultures in most cereals such as maize and wheat have reached the stage where it can be used in breeding programs to some extent and many new cultivars produced by genetic manipulation have now reached the market.


2021 ◽  
Vol 15 (1) ◽  
pp. 12-25
Author(s):  
Tokpapon Eliane Manlé ◽  
Kan Modeste Kouassi ◽  
Brahima André Soumahoro ◽  
Tchoa Koné ◽  
Kouablan Edmond Koffi ◽  
...  

Rainfall scarcity due to climate change is a major constraint that limits cocoa productivity in Côte d'Ivoire. This work aims to regenerate cocoa plants tolerant to water stress using in vitro methods. Staminode and petal explants of the genotypes C1, C9, C14, C15, C16, C18 and C20 were used to produce somatic embryos through two methods. Firstly, somatic embryos were induced under stressfull conditions on media containing different concentrations of polyethylene glycol (PEG) 6000 (0; 25; 50; 75; 100 and 125 g/l) and secondly; under non-stressed conditions. Somatic embryos were placed on a conversion medium in the same stress condition. The number of regenerants decreased with the increase in the concentration of PEG with all genotypes. Only genotypes C1 and C15 regenerated plantlets under water stress conditions. The sensitive genotypes C9, C14, C16, C18 and C20 have not developed plantlets on media containing PEG. The plantlets produced under water deficit conditions exhibited a reduction in stem length and leaves number and an increase in length or offset of the high number of roots. The survival rate of regenerants during acclimatization was higher on the sandsubstrate. The selected genotypes could be used in an improvement program of cocoa production.Keywords: Climate change; plant regeneration; genotype; tolerance; drought; in vitro


2016 ◽  
Vol 8 (4) ◽  
pp. 511-519 ◽  
Author(s):  
Mihaela A. CIOLOCA ◽  
Andreea M. TICAN ◽  
Maria IANOŞI ◽  
Carmen L. BĂDĂRĂU

The current paper aimed to study the in vitro response of potato genotypes to water stress induced by adding sorbitol and polyethylene glycol in the culture medium. The biological material analysed in the experiment was represented by a Romanian line ‘LP 11-1525/1’ and two isogenic lines ‘LI 101’ and ‘LI 102’. For cultures initiation, the line ‘LP 11-1525/1’ was started from meristems and for the other two genotypes true potato seeds were used. The studied potato genotypes behaved differently depending on the analysed parameters and on the treatment applied for drought tolerance. It was noted that the line ‘LP 11-1525/1’ achieved good results for most of the growth parameters studied, and also the lines derived from true potato seeds behaved well, in some cases even exceeding the line derived from meristems. Of the lines derived from true potato seeds, the best performance was noted for line ‘LI 101-6’ in all the analysed parameters, both on sorbitol and PEG medium. In addition, lines ‘LI 101-7’ and ‘LI 102-4’ achieved good results on both variants of medium used to mediate water stress. Therefore, establishing drought tolerance individuals within populations derived from true potato seeds using sorbitol and polyethylene glycol might be applied.


2017 ◽  
Vol 52 (12) ◽  
pp. 1301-1304 ◽  
Author(s):  
Alice Lichs Marssaro ◽  
Lucymeire Souza Morais-Lino ◽  
Jailson Lopes Cruz ◽  
Carlos Alberto da Silva Ledo ◽  
Janay Almeida dos Santos-Serejo

Abstract: The objective of this work was to determine a method to simulate water stress in vitro to select drought-tolerant banana (Musa sp.) genotypes. The BRS Tropical and Prata Anã cultivars were grown in vitro in an MS liquid medium containing sucrose and benzylaminopurine (BAP), supplemented with different concentrations of polyethylene glycol (PEG) or sorbitol. The yield stability index of dry matter was evaluated. Cultivation for 30 days in a medium containing 15 g L-1 PEG or 36.4 g L-1 sorbitol is appropriate to simulate water stress in vitro.


2003 ◽  
Vol 54 (4) ◽  
pp. 389 ◽  
Author(s):  
Phillip A. Jackson ◽  
Terry E. Morgan

Commercially recoverable sugar content in sugarcane (CCS, expressed as a percentage) is a key selection criterion in sugarcane breeding programs. In some sugarcane breeding programs there may be significant operational advantages in measuring CCS early in the crop growth cycle, well before commercial harvesting would normally commence, and in restricting growth by withholding irrigation to reduce cane yield and lodging. Two field experiments were conducted to investigate these effects. The experiments included clones representative of genotypes routinely assessed in the earliest stages of clonal selection in breeding programs. Differences among genotypes for CCS were expressed early when cane had very low CCS (in February or March), and then rates of increase in CCS following that time were similar in most genotypes. Therefore, time of sampling had little effect on ranking of genotypes for CCS, and selection for high CCS could be effective early in the year. Irrigation regime also had little effect on ranking of the clones for CCS, indicating that mild water stress could be imposed with no adverse effect on selection results. The results are discussed in relation to optimising selection procedures and systems in early stage selection trials in sugarcane breeding programs, and better understanding the physiological basis of genetic variation in CCS.


1995 ◽  
Vol 75 (4) ◽  
pp. 871-875 ◽  
Author(s):  
D. Shateryan ◽  
B. E. Coulman ◽  
D. E. Mather

Three cycles of recurrent restricted phenotypic selection for forage yield were carried out in orchardgrass (Dactylis glomerata L. 'Avon' and 'Pennlate') and timothy (Phleum pratense L. 'Salvo' and 'Drummond'). The objectives of this study were to measure the effectiveness of this selection and to assess whether the selection produced any correlated responses on other characters. The three selected cycles and the original populations (cycle 0) were evaluated in both sward and space-planted experiments over a period of 4 yr. For the majority of the years of evaluation, there were no significant (P < 0.05) differences in forage yield among the different selection cycles. Under space-planted evaluation, cycle 3 of Drummond timothy was lower in both forage and seed yield than the other populations. In general, there was a trend to taller plants with greater circumferences in orchardgrass, and shorter, smaller plants in timothy over selection cycles. Selection had little effect on plant persistence and maturity. In conclusion, three cycles of recurrent restricted phenotypic selection were not effective in improving the forage yield of timothy or orchardgrass. Key words: Timothy, Phleum pratense, orchardgrass, Dactylis glomerata, recurrent selection


2021 ◽  
Vol 34 (4) ◽  
pp. 752-762
Author(s):  
CECÍLIA LEÃO PEREIRA RESENDE ◽  
JULIANA BEZERRA MARTINS ◽  
FELIPE RIBEIRO ILARIA ◽  
CARLA MARIANE MACHADO DOS SANTOS ◽  
FABRICIO RODRIGUES

ABSTRACT The objective of this work was to estimate and compare phenotypic and genetic parameters after three cycles of intrapopulation recurrent selection for fresh corn grown under three nutrient availability conditions. Three experiments derived from the same population (MV-003) were conducted to assess the ability of progenies to absorb nutrients, one under adequate fertilization (control; MV-006), one under low nitrogen availability (N; MV-006N), and one under low phosphorus availability (P; MV-006P). The experiments were carried out in randomized blocks, with 64 half-sib progenies and three replications for each nutritional condition. Chlorophyll index, plant height, ear insertion, ear diameter, ear length, unhusked ear yield, and marketable husked ear were evaluated. The populations showed variability for the three nutrient availability conditions. The variability reduced after only three selection cycles; thus, evaluating a higher number of half-sib progenies, above 64, under low N and P availability is indicated. The rates used to identify the most efficient progenies in breeding programs should be close to the appropriate one, with a slow reduction after the selection cycles. The variability will be thus maintained, with a greater possibility of identifying more promising progenies. In addition, the frequency of favorable alleles increases more gradually and effectively. The N and P rate of 60 kg ha-1 is not indicated as a critical level for the initial phase of the program.


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