Variability and genetic basis for migratory behaviour in a spring population of the aphid, Aphis gossypii Glover in the Yangtze River Valley of China

2008 ◽  
Vol 98 (5) ◽  
pp. 491-497 ◽  
Author(s):  
X.D. Liu ◽  
B.P. Zhai ◽  
X.X. Zhang ◽  
H.N. Gu
Keyword(s):  
Life Cycle ◽  
Maternal Effect ◽  
Genetic Basis ◽  
Aphis Gossypii ◽  
Flight Behaviour ◽  
Primary Host ◽  
Flight Duration ◽  
Selection For ◽  
Secondary Host Plants ◽  
Takeoff Angle

AbstractThe population dynamics, development of gonads, takeoff and flight behaviour of Aphis gossypii Glover were investigated in order to test whether there was variation of migratory ability in the spring population. Field surveys showed that not all the aphids overwintering on hibiscus migrated to the secondary host plants, and the host-alternating and host-specific life-cycle forms coexisted in Nanjing, China. Substantial variation in flight capacity of winged individuals, development of gonads and takeoff behaviour were found within the spring population. The frequency distribution of flight duration and the number of ovarioles per individual alatae exhibited two peaks, representing the migratory and sedentary genotypes, respectively. Significant response to directional selection on takeoff behaviour demonstrated the additive genetic component of this variation. Selection for ‘takeoff’ individuals caused a significant increase in takeoff angle from 39.8° in the first selection to 68.7° in the fifth; and, hence, screened out the migratory genotype (M), while selection for the sedentary individuals increased the rate of non-takeoffs significantly, and screened out the sedentary genotype (S). The reciprocal cross, M♀×S♂, produced hybrid offspring performing significantly steeper takeoff angles compared with those from the cross S♀×M♂, suggesting the presence of a maternal effect. On the other hand, takeoff rate was ranked as M♀×S♂=S♀×M♂>M>S, involving no sex-linkage and maternal effect. The coexistence of host-alternating and host-specific life-cycle forms of A. gossypii on the primary host has, as deduced from the present studies, a genetic basis.

Appropriate decision making in energy technology selection for developing countries: The Life Cycle Assessment approach

2021 ◽  
pp. 83-89
Author(s):  
Abeer Ali Khan
Keyword(s):  
Decision Making ◽  
Developing Countries ◽  
Life Cycle Assessment ◽  
Life Cycle ◽  
Technology Selection ◽  
Energy Technology ◽  
High Demand ◽  
Environmentally Conscious ◽  
Assessment Approach ◽  
Selection For

As the high demand of energy of the developing countries is met by importing energy and different energy technology, it has become increasingly necessary to discuss the environmental impacts throughout the life cycle of those technologies and make better decisions. Developed in the late 1960s, Life Cycle Assessment (LCA) has become a wide-ranging tool used to determine impacts of products or systems over several environmental and resource issues. The LCA approach has become more prevalent in research, industry and policy with growing concern for the environment. Therefore, the aim of this paper is to introduce the use of LCA in the decision-making process while selecting an energy technology. In this way, more environmentally conscious decisions will be made as LCAs can provide a better basis for this process.

Compatibility Analysis of Product Design for Recyclability and Reuse

1994 ◽  
Author(s):  
Patrick Di Marco ◽  
Charles F. Eubanks ◽  
Kos Ishii
Keyword(s):  
Life Cycle ◽  
Cost Function ◽  
Product Design ◽  
Material Selection ◽  
Computer Tool ◽  
Compatibility Analysis ◽  
Life Cycle Design ◽  
Environmentally Responsible ◽  
Qualitative Knowledge ◽  
Selection For

Abstract This paper describes a method for evaluating the compatibility of a product design with respect to end-of-life product retirement issues, particularly recyclability. Designers can affect the ease of recycling in two major areas: 1) ease of disassembly, and 2) material selection for compatibility with recycling methods. The proposed method, called “clumping,” involves specification of the level of disassembly and the compatibility analysis of each remaining clump with the design’s post-life intent; i.e., reuse, remanufacturing, recycling, or disposal. The method uses qualitative knowledge to assign a normalized measure of compatibility to each clump. An empirical cost function maps the measure to an estimated cost to reprocess the product. The method is an integral part of our life-cycle design computer tool that effectively guides engineers to an environmentally responsible product design. A refrigerator in-door ice dispenser serves as an illustrative example.

Heterozygote advantage and the evolution of a dominant diploid phase.

Genetics ◽  
1992 ◽  
Vol 132 (4) ◽  
pp. 1195-1198 ◽  
Author(s):  
D B Goldstein
Keyword(s):  
Life Cycle ◽  
Sexual Reproduction ◽  
Genetic Factor ◽  
Higher Plants ◽  
Heterozygote Advantage ◽  
Seed Plants ◽  
Sexual Species ◽  
Evolutionary Forces ◽  
Eukaryotic Species ◽  
Selection For

Abstract The life cycle of eukaryotic, sexual species is divided into haploid and diploid phases. In multicellular animals and seed plants, the diploid phase is dominant, and the haploid phase is reduced to one, or a very few cells, which are dependent on the diploid form. In other eukaryotic species, however, the haploid phase may dominate or the phases may be equally developed. Even though an alternation between haploid and diploid forms is fundamental to sexual reproduction in eukaryotes, relatively little is known about the evolutionary forces that influence the dominance of haploidy or diploidy. An obvious genetic factor that might result in selection for a dominant diploid phase is heterozygote advantage, since only the diploid phase can be heterozygous. In this paper, I analyze a model designed to determine whether heterozygote advantage could lead to the evolution of a dominant diploid phase. The main result is that heterozygote advantage can lead to an increase in the dominance of the diploid phase, but only if the diploid phase is already sufficiently dominant. Because the diploid phase is unlikely to be increased in organisms that are primarily haploid, I conclude that heterozygote advantage is not a sufficient explanation of the dominance of the diploid phase in higher plants and animals.

Evidence for selection for the tyrosine-86 allele of the pfmdr 1 gene of Plasmodium falciparum by chloroquine and amodiaquine

Parasitology ◽  
1997 ◽  
Vol 114 (3) ◽  
pp. 205-211 ◽  
Author(s):  
M. T. DURAISINGH ◽  
C. J. DRAKELEY ◽  
O. MULLER ◽  
R. BAILEY ◽  
G. SNOUNOU ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Plasmodium Falciparum ◽  
Genetic Basis ◽  
Drug Trial ◽  
Enzyme Digestion ◽  
Restriction Enzyme Digestion ◽  
Blood Samples ◽  
Allelic Status ◽  
Group A ◽  
Selection For

The 4-aminoquinolines chloroquine (CQ) and amodiaquine (AM) were used to treat Gambian children with uncomplicated falciparum malaria in a randomized drug trial. Blood samples were taken immediately before treatment (day 0), and at day 7 and day 28 after treatment. Samples from those parasitologically positive at day 7 following treatment (‘early positives’) and those positive at day 28 but negative at day 7 (‘late positives’) have been studied by PCR followed by restriction enzyme digestion to determine the allelic status of the pfmdr 1 locus at the codon-86 position (asparagine or tyrosine), previously associated with resistance to CQ. A significantly higher prevalence of the tyr-86 allele was observed in samples taken immediately before treatment (day 0) in the early positives group when compared with the late positives group. This suggests the tyr-86 allele contributes to drug resistance in the early positives group. This association remained significant for both CQ and AM groups, implying a common genetic basis of resistance. Predominance of the allele at day 7 is consistent with a strong selection in the first week following treatment. In the late positives group, a significantly higher prevalence of the tyr-86 allele was observed in the samples at day 28 when compared with those at day 0, suggestive of selection during the period day 7 to day 28. Differences were observed in the extent of this selection in the CQ and AM groups. The samples were genotyped at 3 unlinked polymorphic loci. These analyses suggested that most parasites observed at day 7 were probably recrudescences whereas most of those at day 28 were reinfections.

Preliminary evaluation of genetic variation of weevil resistance in interior spruce in British Columbia

1991 ◽  
Vol 21 (2) ◽  
pp. 230-234 ◽  
Author(s):  
G. K. Kiss ◽  
A. D. Yanchuk
Keyword(s):  
British Columbia ◽  
Genetic Basis ◽  
Diameter Growth ◽  
Preliminary Evaluation ◽  
White Pine ◽  
North Central ◽  
Interior Spruce ◽  
Progeny Tests ◽  
Selection For ◽  
White Pine Weevil

White pine weevil (Pissodesstrobi (Peck)) damage in three interior spruce open-pollinated progeny tests in north central British Columbia was evaluated to examine the patterns of attack among families. While the overall incidence of damage was different across sites (i.e., Quesnel 9%, Red Rock 37%, and Aleza Lake 63%), correlations on a family-mean basis (percentage attacked per family) at Red Rock and Quesnel as well as Red Rock and Aleza Lake were significant (r = 0.63 and 0.71, respectively). Estimates of family heritability across sites for damage was high (hf = 0.77 ± 0.11), but individual heritability was only moderate (hi = 0.18 ± 0.03). More vigorous families, as determined by 10-year family mean height superiority prior to weevil attack, were damaged less frequently than those with average and poorer performance. Negative correlations of mean family height at 10 years of age with incidence of damage (on a family-mean basis) and mean family diameter with incidence of damage were significant (r = −0.51 and −0.44, respectively). These data suggest that there is a moderate genetic basis for resistance to weevil attack in interior spruce and that selection for height and diameter growth may improve resistance to weevil attack.

scholarly journals Genetic dissection of yield-related traits and mid-parent heterosis for those traits in maize (Zea mays L.)

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Qiang Yi ◽  
Yinghong Liu ◽  
Xianbin Hou ◽  
Xiangge Zhang ◽  
Hui Li ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Recombinant Inbred Lines ◽  
Kernel Weight ◽  
Genetic Dissection ◽  
Hybrid Mapping ◽  
Maize Breeding ◽  
Phenotypic Variations ◽  
Selection For ◽  
Genomic Regions ◽  
Mapping Populations

Abstract Background Utilization of heterosis in maize could be critical in maize breeding for boosting grain yield. However, the genetic architecture of heterosis is not fully understood. To dissect the genetic basis of yield-related traits and heterosis in maize, 301 recombinant inbred lines derived from 08 to 641 × YE478 and 298 hybrids from the immortalized F2 (IF2) population were used to map quantitative trait loci (QTLs) for nine yield-related traits and mid-parent heterosis. Results We observed 156 QTLs, 28 pairs of loci with epistatic interaction, and 10 significant QTL × environment interactions in the inbred and hybrid mapping populations. The high heterosis in F1 and IF2 populations for kernel weight per ear (KWPE), ear weight per ear (EWPE), and kernel number per row (KNPR) matched the high percentages of QTLs (over 50%) for those traits exhibiting overdominance, whereas a notable predominance of loci with dominance effects (more than 70%) was observed for traits that show low heterosis such as cob weight per ear (CWPE), rate of kernel production (RKP), ear length (EL), ear diameter (ED), cob diameter, and row number (RN). The environmentally stable QTL qRKP3–2 was identified across two mapping populations, while qKWPE9, affecting the trait mean and the mid-parent heterosis (MPH) level, explained over 18% of phenotypic variations. Nine QTLs, qEWPE9–1, qEWPE10–1, qCWPE6, qEL8, qED2–2, qRN10–1, qKWPE9, qKWPE10–1, and qRKP4–3, accounted for over 10% of phenotypic variation. In addition, QTL mapping identified 95 QTLs that were gathered together and integrated into 33 QTL clusters on 10 chromosomes. Conclusions The results revealed that (1) the inheritance of yield-related traits and MPH in the heterotic pattern improved Reid (PA) × Tem-tropic I (PB) is trait-dependent; (2) a large proportion of loci showed dominance effects, whereas overdominance also contributed to MPH for KNPR, EWPE, and KWPE; (3) marker-assisted selection for markers at genomic regions 1.09–1.11, 2.04, 3.08–3.09, and 10.04–10.05 contributed to hybrid performance per se and heterosis and were repeatedly reported in previous studies using different heterotic patterns is recommended.

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