Cytogenetics of F1 hybrids between Cajanus and Atylosia species and its phylogenetic implications

1985 ◽  
Vol 71 (2) ◽  
pp. 216-220 ◽  
Author(s):  
R. P. S. Pundir ◽  
R. B. Singh
Author(s):  
David H. Sturm ◽  
Bob F. Perkins

Each of the seven families of rudists (Mollusca, Bivalvia, Hippuritacea) is characterized by distinctive shell-wall architectures which reflect phylogenetic relationships within the superfamily. Analysis of the complex, calcareous, cellular wall of the attached valve of the radiolite rudist Eoradiolites davidsoni (Hill) from the Comanche Cretaceous of Central Texas indicates that its wall architecture is an elaboration of the simpler monopleurid rudist wall and supports possible radiolite-monopleurid relationships.Several well-preserved specimens of E. davidsoni were sectioned, polished, etched, and carbon and gold coated for SEM examination. Maximum shell microstructure detail was displayed by etching with a 0.7% HC1 solution from 80 to 100 seconds.The shell of E. davidsoni comprises a large, thick-walled, conical, attached valve (AV) and a small, very thin, operculate, free valve (FV) (Fig. 1a). The AV shell is two-layered with a thin inner wall, in which original structures are usually obliterated by recrystallization, and a thick, cellular, outer wall.


Author(s):  
R. E. Kazakhmedov ◽  
М. А Magomedova

One of the modern selection tasks in vegetable growing is quality products improving, obtaining high yields of environmentally safe wide assortment vegetables. To the new varieties of vegetable crops including winter white cabbage are specified new requirements such as market competitiveness, resistance to unfavorable environmental conditions, heat resistance of the varieties and F1 hybrids. The article is shown investigation results about studies of exogenous treatment by solutions on the base of physiologically active compounds of hormonal nature on the started process of stem extension stage activation and flowering of winter white cabbage plants. For the first time in the Dagestan conditions has been studied the possibility of hormonal regulation of the premature stem extension stage and flowering prevention of winter white cabbage after the initiation of natural induction. In our studies with an early planting there are not more than 20% of blooming plants, most varieties showed a high propensity to premature stem extension stage and flowering. The possibility of the hormonal exogenous regulation of the unfavorable winter white cabbage flowering has been revealed. The most pronounced effect on the transition to stem extension stage and flowering were provided by auxin nature preparations. In particular, treatment with NAS at a dose of 5 mg / l significantly reduced the number of blossom plants, krezatsin (50 mg / l) had a similar effect, but it was less pronounced. The use of cabbage in winter crops makes it possible to obtain two or three yields per year from the same area. Creation and introduction into production of promising and high-yielding varieties and hybrids will allow increasing production and reducing its cost.


Author(s):  
O. V. Gladysheva ◽  
Т. А. Barkovskaya

This article presents the results of a study of hybrid spring wheat populations. Revealed different patterns of inheritance of important traits in F1 hybrids, which is caused by hereditary features of the original forms and circumstances. Analysis of hybrid populations showed that the dominant role in the formation of 1000 grains mass belongs to productivity and weight of grain with an ear, correlation coefficient r = 0.90 and amounted to r = 0.73, respectively. Found that the hybrid population in F4-5, created on the basis of grades Moscow 35, Esther, Agatha, Rome, Saratovskaya 29 (Russia), Ostinka (Ukraine) are a valuable material for selection of highly productive genotypes for future use breeding process. 


1958 ◽  
Vol 50 (11) ◽  
pp. 714-715 ◽  
Author(s):  
J. P. Craigmiles ◽  
H. B. Harris ◽  
J. P. Newton ◽  
J. W. Dobson
Keyword(s):  

2018 ◽  
Vol 5 (04) ◽  
Author(s):  
SS SOLANKEY ◽  
ANIL K SINGH

Fifty one okra F1 hybrids (using 17 lines as female and 3 testers as male parent) were evaluated in RCBD design during two different consecutive seasons (summer and rainy). Phenotypic coefficient of variability (PCV) was higher than genotypic coefficient of variability (GCV) for all studied character exhibiting environmental effects on the expression of characters. Heritability (h2b) along with genetic advance per cent of mean was found highest for character YVMV (86.95% and 150.61%). All the 51 okra hybrids were grouped into 4 distinct clusters in which Cluster II was the largest cluster having 28 F1s (54.90% of total F1s) followed by Cluster I with 14 F1s (27.45% of total F1s). Out of the major 6 PCs, 4 principal components (PC1, PC2, PC3 and PC4) accounted with proportionate values of 22.61, 17.22, 11.87 and 10.63%, respectively and contributed 62.33 % of the cumulative variation having Eigen value more than one. Moreover, based on PCs and genetic divergence in Cluster I and Cluster IV for plant height, YVMV and number of fruit per plant is important to identify the best cross combination (Arka Abhay × Arka Anamika) in okra. Therefore, the best cross combinations for improvement in various economic traits can be recommended on the basis of genetic divergence and principal component analysis in okra.


1977 ◽  
Vol 146 (2) ◽  
pp. 571-578 ◽  
Author(s):  
M E Dorf ◽  
J H Stimpfling

The ability of various B10 congenic resistant strains to respond to the alloantigen H-2.2 was tested. High and low antibody-producing strains were distinguished by their anti-H-2.2 hemagglutinating respones. However, these strains do not differ in their ability to respond to these antigenic differences in the mixed lymphocyte culture. The humoral response to the H-2.2 alloantigen was shown to be controlled by two interacting genes localized within the H-2 complex. Thus, F1 hybrids prepared between parental low responder strains could yield high level immune responses. In addition, strains bearing recombinant H-2 haplotypes were used to map the two distinct genes controlling the immune response. The alleles at each locus were shown to be highly polymorphic as evidenced by the asymmetric complementation patterns observed. The restricted interactions of specific alleles was termed coupled complementation. The significance of the results in the terms of mechanisms of Ir gene control are discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Can Yuan ◽  
Xiufen Sha ◽  
Miao Xiong ◽  
Wenjuan Zhong ◽  
Yu Wei ◽  
...  

AbstractLigusticum L., one of the largest members in Apiaceae, encompasses medicinally important plants, the taxonomic statuses of which have been proved to be difficult to resolve. In the current study, the complete chloroplast genomes of seven crucial plants of the best-known herbs in Ligusticum were presented. The seven genomes ranged from 148,275 to 148,564 bp in length with a highly conserved gene content, gene order and genomic arrangement. A shared dramatic decrease in genome size resulted from a lineage-specific inverted repeat (IR) contraction, which could potentially be a promising diagnostic character for taxonomic investigation of Ligusticum, was discovered, without affecting the synonymous rate. Although a higher variability was uncovered in hotspot divergence regions that were unevenly distributed across the chloroplast genome, a concatenated strategy for rapid species identification was proposed because separate fragments inadequately provided variation for fine resolution. Phylogenetic inference using plastid genome-scale data produced a concordant topology receiving a robust support value, which revealed that L. chuanxiong had a closer relationship with L. jeholense than L. sinense, and L. sinense cv. Fuxiong had a closer relationship to L. sinense than L. chuanxiong, for the first time. Our results not only furnish concrete evidence for clarifying Ligusticum taxonomy but also provide a solid foundation for further pharmaphylogenetic investigation.


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