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11.
12.
Imad Mennai Esma Lamera Nabila Slougui Brahim Benaicha Salim Gasmi Zakaria Samai Naima Rahmouni Chawki Bensouici Diana C. G. A. Pinto 《化学与生物多样性》2021,18(9):e2100278
This work aimed to investigate, for the first time, the chemical composition, antioxidant, antiparasitic, cytotoxicity, and antimicrobial activities of the aromatic plant Limonium oleifolium Mill. essential oil (EO) and organic extracts. L. oleifolium aerial parts essential oil was analyzed by GC-FID and GC-MS, and 46 constituents representing 98.25±1.12 % of the oil were identified. γ-Muurolene (10.81±0.07 %), cis-caryophyllene (7.71±0.06 %), o-cymene (7.07±0.01 %) and α-copaene (5.02±0.05 %) were the essential oil main compounds. The antioxidant activity of L. oleifolium EO and organic extracts (MeOH, CHCl3, AcOEt, BuOH) was explored using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ABTS, β-carotene/linoleic acid, cupric reducing antioxidant capacity (CUPRAC), and ferric reducing power assays. The results showed that L. oleifolium EO exhibit antioxidant capacity (IC50=17.40±1.32 μg/mL for DPPH assay, IC50=29.82±1.08 μg/mL for β-carotene assay, IC50=25.23±1.01 μg/mL for ABTS assay, IC50=9.11±0.08 μg/mL for CUPRAC assay and IC50=19.41±2.06 mg/mL for reducing power assay). Additionally, the EO showed significant activity against trophozoite form of Acanthamoeba castellanii (IC50=7.48±0.41 μg/mL) and promastigote form of Leishmania amazonensis (IC50=19.36±1.06 μg/mL) and low cytotoxicity on murine macrophages (LC50 90.23±1.09 μg/mL), as well as good antimicrobial activity against Staphylococcus aureus, Escherichia coli, Klebsiella oxytoca, and Pseudomonas aeruginosa. These results suggest that L. oleifolium essential oil is a valuable source of bioactive compounds presenting antioxidant, antiparasitic, and antimicrobial activities. Furthermore, it is considered nontoxic. 相似文献
13.
14.
Intrasexual competition is an important selective force that can favor the evolution of honest signals of fighting ability. Research has focused predominantly on male birds, but many female birds also possess plumage ornaments that could mediate the outcome of competitive interactions. We examined the relationship between blue and white structural coloration and aggression in female tree swallows Tachycineta bicolor. Tree swallows are secondary cavity nesters and females show delayed plumage maturation which may be related to intense competition for nest sites. We compared plumage reflectance of second‐year (SY) and after‐second year (ASY) females, and within‐individual changes in plumage reflectance of ASY females in two successive years. We assessed aggression by placing a caged SY female 2 m from the nest box of an ASY female and quantified the ASY female's response in relation to her own plumage coloration. We found substantial differences in plumage reflectance of SY and ASY females, but found that ASY females became greener with duller white coloration in the second year. This may be due to poor weather that made reproduction particularly costly in the first year of the study and suggests coloration is influenced by condition. We found no relationship between dorsal coloration and aggressiveness. Rather, brighter white females spent more time on their nest box and within 2 m of the intruder than females with dull breasts. Our findings suggest that brighter white ASY females may perceive a SY female as less of a threat or that there may be a trade‐off associated with aggression and parental care that is related to white brightness. 相似文献
15.
Mapping of post-flowering drought resistance traits in grain sorghum: association between QTLs influencing premature senescence and maturity 总被引:13,自引:0,他引:13
Crasta OR Xu WW Rosenow DT Mullet J Nguyen HT 《Molecular & general genetics : MGG》1999,262(3):579-588
The identification of genetic factors underlying the complex responses of plants to drought stress provides a solid basis
for improving drought resistance. The stay-green character in sorghum (Sorghum bicolor L. Moench) is a post-flowering drought resistance trait, which makes plants resistant to premature senescence under drought
stress during the grainfilling stage. The objective of this study was to identify quantitative trait loci (QTLs) that control
premature senescence and maturity traits, and to investigate their association under post-flowering drought stress in grain
sorghum. A genetic linkage map was developed using a set of recombinant inbred lines (RILs) obtained from the cross B35 × Tx430,
which were scored for 142 restriction fragment length polymorphism (RFLP) markers. The RILs and their parental lines were
evaluated for post-flowering drought resistance and maturity in four environments. Simple interval mapping identified seven
stay-green QTLs and two maturity QTLs. Three major stay-green QTLs (SGA, SGD and SGG) contributed to 42% of the phenotypic
variability (LOD 9.0) and four minor QTLs (SGB, SGI.1, SGI.2, and SGJ) significantly contributed to an additional 25% of the
phenotypic variability in stay-green ratings. One maturity QTL (DFB) alone contributed to 40% of the phenotypic variability
(LOD 10.0), while the second QTL (DFG) significantly contributed to an additional 17% of the phenotypic variability (LOD 4.9).
Composite interval mapping confirmed the above results with an additional analysis of the QTL × Environment interaction. With
heritability estimates of 0.72 for stay-green and 0.90 for maturity, the identified QTLs explained about 90% and 63% of genetic
variability for stay-green and maturity traits, respectively. Although stay-green ratings were significantly correlated (r=0.22, P ≤ 0.05) with maturity, six of the seven stay-green QTLs were independent of the QTLs influencing maturity. Similarly, one
maturity QTL (DFB) was independent of the stay-green QTLs. One stay-green QTL (SGG), however, mapped in the vicinity of a
maturity QTL (DFG), and all markers in the vicinity of the independent maturity QTL (DFB) were significantly (P ≤ 0.1) correlated with stay-green ratings, confounding the phenotyping of stay-green. The molecular genetic analysis of the
QTLs influencing stay-green and maturity, together with the association between these two inversely related traits, provides
a basis for further study of the underlying physiological mechanisms and demonstrates the possibility of improving drought
resistance in plants by pyramiding the favorable QTLs.
Received: 10 October 1998 / Accepted: 12 July 1999 相似文献
16.
High levels of extra-pair paternity in an isolated, low-density, island population of tree swallows (Tachycineta bicolor) 总被引:1,自引:0,他引:1
Conrad KF Johnston PV Crossman C Kempenaers B Robertson RJ Wheelwright NT Boag PT 《Molecular ecology》2001,10(5):1301-1308
Molecular genetic studies have suggested that apparently nonbreeding males ('floaters') may account for a significant proportion of extra-pair paternity (EPP) in avian populations. Attempts to determine the influence of breeding density on EPP are therefore confounded by the presence of a subpopulation of floaters whose numbers are difficult to estimate. To study EPP in a tree swallow (Tachycineta bicolor) population with few floaters, we chose a nestbox grid on an island with an excess of available breeding sites and very few floaters. We obtained DNA samples from 13 complete families and performed DNA profiling on them using four microsatellite loci. For comparison, we also obtained a sample of 58 extra-pair young (EPY) from a mainland population typed at five microsatellite loci. Paternity assignments among resident males in both populations were made using the microsatellite profiles and a likelihood-based statistical method. Of the 67 island nestlings typed, we found 37 (55%) nestlings from 11 (85%) different nests that were EPY. The proportion of nestlings that were EPY and the proportion of broods containing EPY did not differ significantly between island and mainland populations studied previously. There was no significant difference between island and mainland populations in the proportion of extra-pair paternities assigned among neighbouring resident males. Male breeding density does not appear to affect the ability of female tree swallows to obtain extra-pair fertilizations, at least over the range of densities studied so far. The rate of EPP has remained remarkably consistent over many years, studies and populations implying an important role of active female choice in determining EPP. 相似文献
17.
Most studies of tiller development have not related the physiological and morphological features of each culm to its subsequent fertility. This introduces problems when trying to account for the effects of tillering on yield in crop models. The objective of this study was to detect the most likely early determinants of tiller fertility in sorghum by identifying hierarchies for emergence, fertility and grain number of tillers over a wide range of assimilate availabilities. Emergence, phenology, leaf area development and dry weight partitioning were quantified weekly for individual tillers and main culms of tillering and uniculm plants grown at one of four densities, from two to 16 plants m(-2). For a given plant in any given density, the same tiller hierarchy applied for emergence of tillers, fertility of the emerged tillers and their subsequent grain number. These results were observed over a range of tiller fertility rates (from 7 to 91%), fertile tiller number per plant at maturity (from 0.2 to 4.7), and tiller contribution to grain yield (from 5 to 78 %). Tiller emergence was most probably related to assimilate supply and light quality. Development, fertility and contribution to yield of a specific tiller were highly dependent on growing conditions at the time of tiller emergence, particularly via early leaf area development of the tiller, which affected its subsequent leaf area accumulation. Assimilate availability in the main culm at the time of tiller emergence was the most likely early determinant of subsequent tiller fertility in this study. 相似文献
18.
Tillering in grain sorghum over a wiide range of population densities: modelling dynamics of tiller fertility 总被引:2,自引:0,他引:2
The prediction of tillering is poor or absent in existing sorghum crop models even though fertile tillers contribute significantly to grain yield. The objective of this study was to identify general quantitative relationships underpinning tiller dynamics of sorghum for a broad range of assimilate availabilities. Emergence, phenology, leaf area development and fertility of individual main culms and tillers were quantified weekly in plants grown at one of four plant densities ranging from two to 16 plants m(-2). On any given day, a tiller was considered potentially fertile (a posteriori) if its number of leaves continued to increase thereafter. The dynamics of potentially fertile tiller number per plant varied greatly with plant density, but could generally be described by three determinants, stable across plant densities: tiller emergence rate aligned with leaf ligule appearance rate; cessation of tiller emergence occurred at a stable leaf area index; and rate of decrease in potentially fertile tillers was linearly related to the ratio of realized to potential leaf area growth. Realized leaf area growth is the measured increase in leaf area, whereas potential leaf area growth is the estimated increase in leaf area if all potentially fertile tillers were to continue to develop. Procedures to predict this ratio, by estimating realized leaf area per plant from intercepted radiation and potential leaf area per plant from the number and type of developing axes, are presented. While it is suitable for modelling tiller dynamics in grain sorghum, this general framework needs to be validated by testing it in different environments and for other cultivars. 相似文献
19.
L. A. Elkonin V. V. Kozhemyakin A. G. Ishin 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(4):626-632
The genetics of male-fertility restoration in sorghum in the “9E” and A4 CMS-inducing cytoplasms, was studied by crossing
a number of fertility restorer lines of A1 cytoplasm to CMS lines [9E]T×398 and [A4]T×398 and the line [9E]Milo-10, which
was obtained by backcrossing Milo-10 to [9E]T×398. It was revealed that both A4 and “9E” cytoplasms are characterized by a
sporophytic mode of restoration of male fertility. Depending on the nuclear background of the male parents, fertility restoration
was controlled by one or two dominant genes. Fertility-restorer genes of one of the tester lines, KVV-114, were effective
in [9E]T×398 but could not restore [9E]Milo-10. A fertile line obtained from the fertile hybrid [9E]T×398/KVV-112, with “9E”
cytoplasm, also failed to restore [9E]Milo-10. In a number of hybrid combinations with both A4 and “9E” cytoplasms a novel
and unusual phenomenon of gradual restoration of male fertility in subsequent backcross generations was observed. Pollen from
the fertile revertants did not transmit fertility restoration in progeny from crosses with the original CMS line and was poorly
transmitted in sib-crosses. The appearance of fertile revertants and the different reactions of different CMS lines with the
same cytoplasm in test-crosses may be caused by the action of recessive nuclear genes of the recurrent male parents that were
accumulated during backcrossing; these may induce changes in cytoplasmic genes controlling CMS.
Received: 5 March 1998 / Accepted: 7 April 1998 相似文献
20.
C4 photosynthesis is functionally dependent on metabolic interactions between mesophyll and bundle-sheath cells. Although the C4 cycle is biochemically well understood many aspects of the regulation of enzyme activities, gene expression and cell differentiation are elusive.Protein kinases are likely involved in these regulatory processes providing links to hormonal, metabolic and developmental signal transduction pathways. We have identified several protein kinases that are differentially expressed in mesophyll and bundle-sheath cells of the C4 plant Sorghum bicolor. Here we describe the characterization of two putative protein kinases that show high similarity to the SNF1/AMPK family of protein serine/threonine kinases. The mRNA of both kinases accumulates to much higher levels in mesophyll cells than in the bundle-sheath and can also be detected in root tissue. Complementation experiments with a snf1 mutant of Saccharomyces cerevisiae indicate that the S. bicolor protein kinase SNFL1 does not represent a functional homologue of the yeast SNF1 protein kinase. 相似文献