Search

Copyright of Bulletin of Botanical Research is the property of Bulletin of Botanical Research Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chimeras are universal phenomena in the M1-generation plants obtained following radiation-induced mutagenesis; however, the mutational effects and variant inheritance mechanisms of related rice chimeras have yet to be sufficiently clarified. In this study, we used target capture-seq technology to obtain OsNramp5 mutant chimeras via carbon ion beam irradiation, and used a 10 kb liquid chip to determine the SNP/InDel mutational occurrence and genetic isolation characteristics of the chimeric M1 generation and mutational M2 genomes. The results revealed that the mutation detected in the OsNramp5 gene of M1 chimeric rice was not inherited by the M2 generation; that is, the mutation detected in somatic cells of the M1 population was not passed to the subsequent generation via the germ cells. In addition, conversion was established to be twice as common as transversion among the M1 genomic mutation types, although more than half of the variant sites were inherited by the M2 generation. However, these sites were rarely located within the functional coding regions of genes. Our findings in this study revealed the genomic variation characteristics of somatic M1-generation chimeras induced by carbon ion beam irradiation and their genetic characteristics in the M2 generation. These findings will provide a reference for further studies that seek to elucidate the mechanisms underlying chimeric mutation effects and for selecting appropriate procedures for mutagenesis breeding following carbon ion beam irradiation.

Copyright of Biology Teaching is the property of East China Normal University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[ Objective]The purpose of this study was to analyze the associations of the VIP ( Vasoactive intestinal peptide, VIP), VIPR-1 ( Vasoactive intestinal peptide receptorl, VIPR-1) and VIPR-2 gene with chicken reproduction traits and find important markers for these traits. [ Method] PCR sequencing was used to detect the variation in the coding region of VIP gene, part of the intron region, and part of the sequence regions of VIPR-1 and VIPR-2 genes, and to analyze the association with reproductive traits. [Result] In the Yaoshan chicken pop ulation, one intron mutation site was detected for VIP gene, one coding region mutation site, one insert/ deletion mutation site and 14 intron region SNP sites were detected for VIPR-1 gene, and one coding region mutation site and two intron mutation sites were detected for VIPR-2 gene. 6 mutation sites (39 109, 39 114, 39 227, 68 817, 69 061, 97 123) of the VIPR-1 gene and 3 mutation sites ( 3739, 3184, 49 246) of the VIPR-2 gene were significantly associated with the total egg number with 300 d of age and broodiness traits ( P < 0. 05 or P < 0. 01). [Conclusion] The above polymorphic loci can be used as assisted selection markers for the reproductive traits of Llbo Y aoshan chick [ABSTRACT FROM AUTHOR]

Premise of research. Angiosperms are commonly classified as self-incompatible or self-compatible. This dichotomy has influenced research on the ecological and demographic consequences of colonization because of the predicted benefits of self-compatibility for establishment at low density. Some individuals of self-incompatible species, however, exhibit partial self-incompatibility (PSI), meaning that they set variable amounts of seed following self-pollination. Here, we investigate genetic and environmental components of PSI in tristylous Lythrum salicaria as a context for understanding colonization and the floral morph structure of invasive populations.Methodology. We surveyed variation in PSI using experimental self- and cross-pollinations on plants (n=338) grown under glasshouse conditions. We compared the stability in expression of PSI over 2 yr (n=80), and by pollinating selected clones (n=12) grown under wet and dry conditions. We compared the compatibility status of mid-styled parents (n=14) and their selfed offspring to determine whether there was a genetic component to PSI and whether the expression of PSI, measured as fruit set after self-pollination, differed between segregating long- and mid-styled plants.Pivotal results. Approximately 34% of plants set seed following self-pollination. The mid-styled morph produced more fruit following self-pollination in comparison with the remaining morphs. An index of self-compatibility (ISC) exhibited significant repeatability for individual plants over two successive flowering seasons. There was no systematic influence of wet and dry growing conditions at flowering on PSI, but significant genetic differences among clones in overall expression of PSI were evident. A heritable component to PSI was confirmed by parent-offspring regression, and compatibility values were significantly higher in mid- versus long-styled progeny.Conclusions. Our study demonstrated a weak but significant genetic component to morph-specific variation in PSI. The capacity of the M-morph to set seed after selfing may enable individuals to found populations and contribute to the occurrence of dimorphic populations missing the short-styled morph in the invasive range of L. salicaria. [ABSTRACT FROM AUTHOR]

In natural populations, genetic variation in seasonal male sexual behaviour could affect behavioural ecology and evolution. In a wild-source population of white-footed mice, Peromyscus leucopus , from Virginia, U.S.A., males experiencing short photoperiod show high levels of genetic variation in reproductive organ mass and neuroendocrine traits related to fertility. We tested whether males from two divergent selection lines, one that strongly suppresses fertility under short photoperiod (responder) and one that weakly suppresses fertility under short photoperiod (nonresponder), also differ in photoperiod-dependent sexual behaviour and responses to female olfactory cues. Under short, but not long, photoperiod, there were significant differences between responder and nonresponder males in sexual behaviour and likelihood of inseminating a female. Males that were severely oligospermic or azoospermic under short photoperiod failed to display sexual behaviour in response to an ovariectomized and hormonally primed receptive female. However, on the day following testing, females were positive for spermatozoa only when paired with a male having a sperm count in the normal range for males under long photoperiod. Males from the nonresponder line showed accelerated reproductive development under short photoperiod in response to urine-soiled bedding from females, but males from the responder line did not. The results indicate genetic variation in sexual behaviour that is expressed under short, but not long, photoperiod, and indicate a potential link between heritable neuroendocrine variation and male sexual behaviour. In winter in a natural population, this heritable behavioural variation could affect fitness, seasonal life history trade-offs and population growth. [ABSTRACT FROM AUTHOR]

Highlights: [•] sRNAs play a key role in the maintenance of DNA methylation from parent to progeny. [•] sRNA-mediated mechanisms have the ability to unlock the epigenetic potential of plants. [•] Stress-induced heritable phenotypes are more likely to be due to loss rather than gain of an epigenetic mark. [•] Genomic interactions in hybrids are a source of sRNA-mediated heritable epigenetic variation. [Copyright &y& Elsevier]

Indirect genetic effects ( IGEs) are heritable effects of individuals on trait values of their conspecifics. IGEs may substantially affect response to selection, but empirical studies on IGEs are sparse and their magnitude and correlation with direct genetic effects are largely unknown in plants., Here we used linear mixed models to estimate genetic (co)variances attributable to direct and indirect effects for growth and foliar disease damage in a large pedigreed population of Eucalyptus globulus., We found significant IGEs for growth and disease damage, which increased with age for growth. The correlation between direct and indirect genetic effects was highly negative for growth, but highly positive for disease damage, consistent with neighbour competition and infection, respectively. IGEs increased heritable variation by 71% for disease damage, but reduced heritable variation by 85% for growth, leaving nonsignificant heritable variation for later age growth. Thus, IGEs are likely to prevent response to selection in growth, despite a considerable ordinary heritability., IGEs change our perspective on the genetic architecture and potential response to selection. Depending on the correlation between direct and indirect genetic effects, IGEs may enhance or diminish the response to natural or artificial selection compared with that predicted from ordinary heritability. [ABSTRACT FROM AUTHOR]

Insect herbivores contend with various plant traits that are presumed to function as feeding deterrents. Paradoxically, some specialist insect herbivores might benefit from some of these plant traits, for example by sequestering plant chemical defenses that herbivores then use as their own defense against natural enemies. Larvae of the butterfly species Battus philenor (L.) (Papilionidae) sequester toxic alkaloids (aristolochic acids) from their Aristolochia host plants, rendering larvae and adults unpalatable to a broad range of predators. We studied the importance of two putative defensive traits in Aristolochia erecta: leaf toughness and aristolochic acid content, and we examined the effect of intra- and interplant chemical variation on the chemical phenotype of B. philenor larvae. It has been proposed that genetic variation for sequestration ability is 'invisible to natural selection' because intra- and interindividual variation in host-plant chemistry will largely eliminate a role for herbivore genetic variation in determining an herbivore's chemical phenotype. We found substantial intra- and interplant variation in leaf toughness and in the aristolochic acid chemistry in A. erecta. Based on field observations and laboratory experiments, we showed that first-instar larvae preferentially fed on less tough, younger leaves and avoided tougher, older leaves, and we found no evidence that aristolochic acid content influenced first-instar larval foraging. We found that the majority of variation in the amount of aristolochic acid sequestered by larvae was explained by larval family, not by host-plant aristolochic acid content. Heritable variation for sequestration is the predominant determinant of larval, and likely adult, chemical phenotype. This study shows that for these highly specialized herbivores that sequester chemical defenses, traits that offer mechanical resistance, such as leaf toughness, might be more important determinants of early-instar larval foraging behavior and development compared to plant chemical defenses. [ABSTRACT FROM AUTHOR]

Environmental change often requires evolutionary responses, and therefore understanding the genetic architecture of susceptible populations is essential for predicting their capacity to respond adaptively. However, quantitative genetic studies are rarely targeted at populations considered vulnerable to such environmental perturbations. Here, we assess the level of heritable variation in the ability of embryos to tolerate desiccation stress in Pseudophryne guentheri, a terrestrial-breeding frog that is currently experiencing a drying climate. We applied a North Carolina II breeding design to identify sources of genetic and environmental variance, and genotype-by-environment interactions (GEIs), underlying the expression of embryo survival, hatching times, hatchling mass, size, and shape. Our analysis revealed highly significant effects of water potential and maternal effects on all measured traits, while additive genetic effects were significant for hatchling shape, and nonadditive effects were observed for embryo survival. Interestingly, GEIs, including for some traits complex three-way sire-by-dam-by-environment interactions, were significant, indicating that progeny from certain male-female crosses were more tolerant to water stress than others. These findings suggest a limited capacity of P. guentheri to respond to a drying climate, but also reveal that the detrimental effects of nonviable male-female crosses (i.e., genetic incompatibility) can be masked in benign environments. [ABSTRACT FROM AUTHOR]

A diverse antibody repertoire is essential for an effective adaptive immune response to novel molecular surfaces. Although past studies have observed common patterns of V-segment use, as well as variation in V-segment use between individuals, the relative contributions to variance from genetics, disease, age, and environment have remained unclear. Using high-throughput sequence analysis of monozygotic twins, we show that variation in naive VH and DH segment use is strongly determined by an individual's germ-line genetic background. The inherited segment-use profiles are resilient to differential environmental exposure, disease processes, and chronic lymphocyte depletion therapy. Signatures of the inherited profiles were observed in class switched germ-line use of each individual. However, despite heritable segment use, the rearranged complementarity-determining region-H3 repertoires remained highly specific to the individual. As it has been previously demonstrated that certain V-segments exhibit biased representation in autoimmunity, lymphoma, and viral infection, we anticipate our findings may provide a unique mechanism for stratifying individual risk profiles in specific diseases. [ABSTRACT FROM AUTHOR]

Abstract: Social interactions among individuals are commonly observed in both plants and animals, and may be partly genetically determined. The social effect of an individual does not affect the phenotype of the individual itself, but rather the phenotypes of all other individuals sharing the environment. As an alternative to traditional breeding schemes solely focusing on the direct breeding value affecting the phenotype of the individual itself, selection may be focused on total breeding values, including both direct and social effects. The latter may give a substantial increase in the rate of genetic gain of the population, given existence of significant social genetic effects. However, social effects are only identifiable when individuals are allocated in several groups. Previously, it has been suggested that an optimum design should include many small groups consisting of unrelated individuals, e.g., by randomly allocating individuals to each group (RAN). However, we hypothesize that a design with few (three) families per group (3FAM), and where each family is tested repeatedly in three different groups would be more advantageous. Using stochastic simulations, assuming a full-sib data structure typical for aquaculture breeding schemes, we compared the two designs with respect to accuracy of breeding values and their ability to produce accurate estimates of (co)variance components of direct and social effects. The results showed that the 3FAM design was clearly superior with respect to precision of estimated genetic (co)variance components of social effects and had substantially higher accuracy of both social and total breeding values, compared with the RAN design (16 to 105% increase). The advantage was particularly expressed at scenarios with zero or negative genetic correlation between direct and social genetic effects. [Copyright &y& Elsevier]

Anecdotal evidence points to genetic variation in resistance of cattle to infection with Mycobacterium bovis, the causative agent of bovine tuberculosis (BTB), and published experimental evidence in deer and cattle suggests significant genetic variation in resistance and reactivity to diagnostic tests. However, such genetic variation has not been properly quantified in the United Kingdom dairy cattle population; it is possible that it exists and may be a factor influencing the occurrence of BTB. Using models based on the outcome of the process of diagnosis (ultimate fate models) and on the outcome of a single stage of diagnosis (continuation ratio models, herd test-date models), this study shows that there is heritable variation in individual cow susceptibility to BTB, and that selection for milk yield is unlikely to have contributed to the current epidemic. Results demonstrate that genetics could play an important role in controlling BTB by reducing both the incidence and the severity of herd breakdowns. [ABSTRACT FROM AUTHOR]

A test for heritability of the sex ratio in human genealogical data is reported here, with the finding that there is significant heritability of the parental sex ratio by male, but not female offspring. A population genetic model was used to examine the hypothesis that this is the result of an autosomal gene with polymorphic alleles, which affects the sex ratio of offspring through the male reproductive system. The model simulations show that an equilibrium sex ratio may be maintained by frequency dependent selection acting on the heritable variation provided by the gene. It is also shown that increased mortality of pre-reproductive males causes an increase in male births in following generations, which explains why increases in the sex ratio have been seen after wars, also why higher infant and juvenile mortality of males may be the cause of the male-bias typically seen in the human primary sex ratio. It is concluded that various trends seen in population sex ratios are the result of changes in the relative frequencies of the polymorphic alleles of the proposed gene. It is argued that this occurs by common inheritance and that parental resource expenditure per sex of offspring is not a factor in the heritability of sex ratio variation. [ABSTRACT FROM AUTHOR]

Relationships between growth at sea, smolt size and age at sexual maturation of Atlantic salmon Salmo salar were tested. The fish were offspring of brood stocks sampled in eight Norwegian rivers at latitudes between 59° and 70° N, hatchery reared and released at smolting at the mouth of the River Imsa (59° N). Smolt size influenced the subsequent growth rate of Atlantic salmon. The larger the fish were at release, the slower the yearly length increment at sea. Mean sea age at sexual maturity, measured as proportion of the returning adults attaining sexual maturity at sea age 2 years, was significantly correlated with mean growth rate during the first year at sea and mean smolt size ( r2= 0·74, P < 0·001). Fish attaining maturity at a relatively high sea age were more fast growing during their first year at sea than those maturing at a younger age. The results indicate that high sea age at sexual maturation is a population-specific characteristic and associated with high early growth rate at sea. [ABSTRACT FROM AUTHOR]

Moso bamboo (Phyllostachys edulis (Carriere) J. Houzeau), native to China, is one of the most economically and ecologically important bamboo species. Since the economic interests and the strong clonality, it has been widely cultivated in southern China, which inevitably reduces the natural stands and leads to gene loss in this species. In this study, three natural populations of Moso bamboo distributed in Anhui, Guangxi, and Zhejiang province, were used to analyze the correlation between phenotypic traits, cell structure, and material properties from the perspective of phenotypic, genetic, and environmental. Among those traits and properties, fiber width was correlated with wall thickness at breast height and average nodes length under branch positively. Leaf length was correlated positively with fiber lumen diameter and parenchyma lumen diameter. Furthermore, it showed a very close correlation between moisture content, bending strength, modulus of elasticity, and diameter at breast height, clear height, and leaf length. The lumen diameter of fiber cell wall thickness is positively correlated with bending strength and modulus of elasticity. Density is positively correlated with parenchyma cell wall thickness. The experimental design is relatively detailed and representative, and the workload is huge. This study reflects the research objectives with scientific and rational experiments and data. This study will analyze the differences of various indicators from the perspective of genetic to build a bridge between micro-structure and macro-structure for rational utilization of the whole area of Moso bamboo resources in China. [ABSTRACT FROM AUTHOR]

Low water availability is a leading contributor to mortality of woody seedlings on grasslands, including those of the invasive shrub Prosopis. Increasing atmospheric CO2 concentration could favor some genotypes of this species over others if there exists intraspecific variation in the responsiveness of survivorship to CO2. To investigate such variation, we studied effects of CO2 enrichment on seedling survival in response to uniform rates of soil water depletion in six maternal families of honey mesquite (P. glandulosa Torr. var. glandulosa). Three families each from the arid and mesic extremes of the species' distribution in the southwestern United States were studied in environmentally controlled glasshouses. Relative water content at turgor loss and osmotic potential were not affected by CO2 treatment. Increased atmospheric CO2 concentration, however, increased growth, leaf production and area, and midday xylem pressure potential, and apparently reduced transpiration per unit leaf area of seedlings as soil dried. Consequently, CO2 enrichment about doubled the fraction of seedlings that survived soil water depletion. Maternal families of honey mesquite differed in percentage survival of drought and in several other characteristics, but differences were of similar or of smaller magnitude compared with differences between CO2 treatments. There was no evidence for genetic variation in the responsiveness of survivorship to CO2. By increasing seedling survival of drought, increasing atmospheric CO2 concentration could increase the abundance of honey mesquite where establishment is limited by water availability. Genetic types with superior ability to survive drought today, however, apparently will maintain that advantage in the future. [ABSTRACT FROM PUBLISHER]

We report the characterization of high- and low-sodium-transporting lines developed by intravarietal selection within a cultivar, IR36, of rice (Oryza saliva L.). The purpose was to investigate the mechanistic basis of sodium uptake in material in which differences in salt uptake could be isolated from the many other morphological and physiological characteristics that affect the phenotypic expression of salt tolerance. The lines differed in mean sodium transport by a factor of 2. They differed in vigour and water use efficiency, which are characters that modify the effects of salt transport, by only 12% or 13%. The lines did not differ significantly in other physiological traits that are components of salt resistance: compartmentalization at the leaf and cellular levels. There was a strong correlation between the transport of sodium and a tracer for apoplastic pathways (trisodium, 3-hydroxy-5,8,10-pyrene trisulphonic acid, PTS) in both lines. The regression coefficient for sodium transport on PTS transport was the same in both lines. The individual variation in PTS transport was similar to that in sodium transport, and the variation in the transport of both was very much greater than the variation in any other character studied. The high- sodium-transporting line took up proportionately more PTS than the low-sodium-transporting line. It is concluded that the transpirational bypass flow is of major importance in sodium uptake by rice and that selection for differences in sodium transport has been brought about by selection for heritable differences in the bypass flow. [ABSTRACT FROM AUTHOR]