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Boll weevil (Coleoptera: Curculionidae) survival through cotton gin trash fans.

There is concern that cotton gins may serve as loci for reintroduction of boll weevils, Anthonomus grandis grandis Boheman, to eradicated or suppressed zones when processing weevil-infested cotton from neighboring zones. Previous work has shown that virtually all weevils entering the gin in the seed cotton will be removed before they reach the gin stand. Those not killed by the seed cotton cleaning machinery will be shunted alive into the trash fraction, which passes through a centrifugal trash fan before exiting the gin. The objective of this study was to determine survival potential of boll weevils passed through a trash fan. Marked adult weevils were distributed in gin trash and fed through a 82.6-cm (32.5-in.) diameter centrifugal fan operated across a range of fan-tip speeds. A small number of boll weevils were recovered alive immediately after passage through the fan, but all were severely injured and did not survive 24 h. In another experiment, green bolls infested with both adult- and larval-stage weevils were fed through the fan. Several teneral adults survived 24 h, and there was no evidence that fan-tip speed affected either initial survival of weevils, or the number of unbroken boll locks that could harbor an infesting weevil. Thus, designating a minimum fan-tip speed for ensuring complete kill is not possible for the boll weevil. Experiments suggest that a device installed in a gin that partially crushes or cracks bolls open before entering a trash fan will increase mortality, possibly enough that further precautions would be unnecessary.

Agriculture↗

Modeling the impact of alternative hosts on Helicoverpa zea adaptation to bollgard cotton.

For highly polyphagous cotton, Gossypium hirsutum L., pests such as Helicoverpa zea (Boddie), a substantial portion of the larval population develops on noncotton alternative hosts. These noncotton hosts potentially provide a natural refuge for H. zea, thereby slowing the evolution of resistance to the Bacillus thuringiensis Berliner (Bt)-derived Cry1Ac protein present in Bollgard cotton. Here, we demonstrate how the measured contribution of such alternative hosts can be included in estimating the "effective refuge" present for H. zea and in modeling resistance evolution in this species. A single-gene, two-compartment model was used in which one compartment represented corn, Zea mays L., and cotton that express the Cry1Ac protein or similar proteins, and the other compartment was the effective refuge, made up of a weighted average of non-Bt cotton and noncotton hosts. The effective refuge was estimated for each of six generations of H. zea based upon available data on larval population densities on different hosts and cropping patterns. Model runs were performed for regions centered on three states: Georgia, Mississippi, and North Carolina. Three sets of fitness cost assumptions for the putative resistance gene were used: none, low, and moderate, with either recessive or additive inheritance for resistance and fitness costs. For Georgia and North Carolina, resistance was predicted to take >30 yr to evolve except in the absence of fitness costs. For Mississippi, results were sensitive to fitness costs: >30 yr with moderate costs, 7-14 yr with low costs, and 6-10 yr without such costs.

Animals↗

Soil organic carbon sequestration in cotton production systems of the southeastern United States: a review.

Past agricultural management practices have contributed to the loss of soil organic carbon (SOC) and emission of greenhouse gases (e.g., carbon dioxide and nitrous oxide). Fortunately, however, conservation-oriented agricultural management systems can be, and have been, developed to sequester SOC, improve soil quality, and increase crop productivity. Our objectives were to (i) review literature related to SOC sequestration in cotton (Gossypium hirsutum L.) production systems, (ii) recommend best management practices to sequester SOC, and (iii) outline the current political scenario and future probabilities for cotton producers to benefit from SOC sequestration. From a review of 20 studies in the region, SOC increased with no tillage compared with conventional tillage by 0.48 +/- 0.56 Mg C ha(-1) yr(-1) (H(0): no change, p < 0.001). More diverse rotations of cotton with high-residue-producing crops such as corn (Zea mays L.) and small grains would sequester greater quantities of SOC than continuous cotton. No-tillage cropping with a cover crop sequestered 0.67 +/- 0.63 Mg C ha(-1) yr(-1), while that of no-tillage cropping without a cover crop sequestered 0.34 +/- 47 Mg C ha(-1) yr(-1) (mean comparison, p = 0.04). Current government incentive programs recommend agricultural practices that would contribute to SOC sequestration. Participation in the Conservation Security Program could lead to government payments of up to Dollars 20 ha(-1). Current open-market trading of C credits would appear to yield less than Dollars 3 ha(-1), although prices would greatly increase should a government policy to limit greenhouse gas emissions be mandated.

Agriculture↗

Elevated levels of IL-6, INF-gamma, and TNF-alpha in mice in response to cotton dust are modulated by anti-TNF-alpha antiserum.

Acute pulmonary neutrophilic inflammation triggered by cotton dust exposure is one of the features of organic dust syndrome. Studies with a mouse model have reproduced the inflammation and have shown the presence of tumor necrosis factor-alpha (TNF-alpha) in the bronchoalveolar lavage (BAL) fluid of mice following a 3-h exposure to respirable cotton dust particles. A cover glass technique for cytospin samples of BAL cells resulted in a 42-fold increase in cell count, with 76% neutrophils, 13% lymphocytes, and 10% macrophages, after cotton dust exposure. Immunohistochemical staining of lung specimens with anti-TNF-alpha antiserum revealed TNF in the cells surrounding pulmonary airways and vessels. Cotton dust exposure resulted in elevated TNF-alpha, IL-6, and INF-gamma in BAL fluid, INF-gamma and IL-6 in serum. Administration of anti-TNF-alpha antiserum prior to the organic dust exposure resulted in a marked attenuation of the pulmonary inflammatory cell response, as well as decreased IL-6 and TNF-alpha levels in BAL fluid and decreased IL-6 and INF-gamma in serum. These results indicate TNF modulation of the dust-induced toxic alveolitis and cytokine production.

Acute Disease↗

Measles virus replication in lungs of hispid cotton rats after intranasal inoculation.

Hispid cotton rats were inoculated intranasally with either measles virus (MV) Edmonston, a multipassaged, tissue culture-adapted strain of MV, or with one of three clinical MV isolates that had limited passages (three to five times) in tissue culture cells. MV Edmonston was recovered from the lungs of every (n = 37) hispid cotton rat inoculated with this virus for at least 7 days after virus inoculation. Peak pulmonary titers occurred on Day +4 (3.3-4.4 log10/g lung). Scattered areas of inflammation were observed interstitially in lung sections from infected animals stained with hematoxylin and eosin, and a similar pattern of diffuse fluorescence was seen in cryostat sections stained with an indirect fluorescent antibody procedure specific for virus antigens. Fluorescent antibody and virus isolation studies on lung lavage cells both suggested that lung leukocytes were a primary target of the virus. In contrast to these findings, virus was isolated only sporadically from hispid cotton rats inoculated with any of the clinical measles virus isolates. Despite the restricted growth of MV in these animals, cotton rats may be useful for studying certain aspects of measles virus pathogenesis and for screening potential antiviral compounds in vivo.

Administration, Intranasal↗

Respiratory disease in cotton textile workers in the People's Republic of China. II. Pulmonary function results.

Pulmonary function tests were performed pre and post workshift on 887 textile workers with at least two years of employment in two cotton mills and one silk mill in Shanghai, the People's Republic of China. Environmental sampling was performed with vertical elutriators, and pulmonary function was performed with standardized techniques. Cotton textile workers were found to have greater across-shift decrements in forced expiratory volume in 1 s (FEV1.0) than silk workers. Increasing duration of exposure resulted in increasing acute decrements in FEV1.0, although significant acute decrements were found in workers with less than five years of exposure. The acute changes in FEV 1.0 were noted in both symptomatic and asymptomatic cotton workers, though the difference between the across-shift change in FEV1.0 (delta FEV1.0%) of the byssinotics and nonbyssinotics increased as work duration increased. There was no difference in preshift FEV1.0 between the cotton and silk workers, but several selection factors likely influenced the observations.

Adult↗

Acute bronchoconstriction induced by cotton dust: dose-related responses to endotoxin and other dust factors.

Fifty-four healthy humans, selected for their acute airway responsiveness to cotton dust, had spirometric tests immediately before and after 6 hours of exposure to card-generated cotton dust from seven different cottons (of several grades and growing regions). During exposures, we measured airborne concentrations of viable fungi and bacteria (total and gram negative), vertically elutriated gravimetric dust, and vertically elutriated endotoxin. Correlation between each of these five exposure indices and exposure-related acute changes in forced expiratory volume in 1 s showed a statistically significant relationship between all of the indices except concentration of viable fungi. Of the other four indices, endotoxin was the most highly correlated (r = -0.94; p less than 0.00001), and gravimetric dust was the least correlated (r = -0.34; p less than 0.05). These findings suggest that gram-negative endotoxin may play a major role in the acute pulmonary response to inhaled cotton dust.

Adolescent↗

Sensitivity of selected immunological, hematological, and reproductive parameters in the cotton rat (Sigmodon hispidus) to subchronic lead exposure.

The effect of lead exposure on cellular immunity, hematology, and reproductive and body condition in mature cotton rats (Sigmodon hispidus) was examined. Two groups of 36 cotton rats each were exposed to 0, 100, or 1,000 ppm lead in drinking water for either 7 or 13 weeks, between 31 August and 2 December 1990. Specific and non-specific cell-mediated immunity was assessed by measuring splenocyte proliferative responses to polyclonal mitogens (Concanavalin A and Pokeweed mitogen), in vivo 24-hr delayed-type hypersensitivity, metabolic activity of peritoneal macrophages, spleen mass and cellularity, and immune organ development. General physiological condition was assessed from hematological, morphological, and reproductive measures. Immune function was sensitive to lead exposure based on depressed proliferative responses of cultured splenocytes, smaller popliteal lymph nodes, and larger spleens among cotton rats receiving 1,000 ppm lead. Spleen mass was reduced in cotton rats receiving 100 ppm lead. Total leukocytes, lymphocytes, neutrophils, eosinophils, total splenocyte yield, packed cell volume, hemoglobin, and mean corpuscular hemoglobin were sensitive to lead exposure. Effects of lead exposure on general condition and reproductive parameters included reduced mass of liver, seminal vesicles, and epididymes in males following a 7-week exposure. Histopathologic changes reflected lead toxicity and included altered renal proximal tubular epithelium, renal intranuclear inclusions, and in some cases, lowered numbers of sperm and developing follicles. In general, lesions were more pronounced with increased lead concentration and longer exposure.

Adrenal Glands↗

[Study on the health of cotton mill workers].

A group of 110 workers in a cotton mill was investigated by questionnaire, skin testing, and the measurement of airway responsiveness through forced expiratory volume for one second(FEV1) by spirometry. The workers were examined before starting work, 10 weeks and one year after exposure. Decreases in FEV1 over shifts were small at 10 weeks and one year, and were slightly higher among people with positive skin reactions to cotton dust extracts. Airway responsiveness, defined as the average decrease in FEV1 after 1.25 mg methacholin, was increased at 10 weeks. It remained about the same after one year, except in the workers with positive skin test. Subjective symptoms of chest tightness and cough with phlegm increased progressively at 10 weeks and one year. Nasal irritation remained unchanged and dry cough decreased in one year. The results suggest that the airway inflammation caused by cotton dust increases with the exposure time and that the changes are more notable in workers with reactivity to cotton dust extract.

Adolescent↗

Pulmonary response of mice to aqueous cotton dust extract.

OBJECTIVE: To determine the pulmonary response of mice to acute exposure of aqueous cotton dust extract (CDE). DESIGN: CDE was made from a standard cotton mill dust. Under mild anaesthesia, 0.05 ml of CDE was instilled intratracheally in balb/c mice. The same volume of sterile isotonic saline was instilled in controls. After 1, 5 and 10, days animals were given an overdose of pentobarbital by intraperitoneal injection, and the upper thorax was opened to expose the trachea. An incision was made and cannulae was inserted. Bronchoalveolar lavage (BAL) was done by instilling, phosphate buffer saline. Total and differential counts were done. The lavage supernatant was assayed for protein. SETTING: The laboratory of Division of Pulmonary and Critical Care Medicine, Duke University Medical Center, USA. ANIMALS: Balb/c mice. MAIN OUTCOME MEASURES: Post-exposure acute effects at bronchoalveolar level. RESULTS: Total and differential cell counts in BAL fluid were significantly higher in CDE exposed compared to controls (P < 0.01). The total mean values (expressed as cells x 10(4)) after exposure for days 1, 5 and 10 were 193.4 +/- 8.6, 177.8 +/- 7.7 and 113.5 +/- 6.4 respectively versus controls (41.6 +/- 3.4). Differential counts (cell no. x 10(4)) revealed 124.3 +/- 6.8, 94.2 +/- 7.9, 19.9 +/- 3.5 polymorph neutrophils (PNM) and 67.3 +/- 7.1, 81.6 +/- 9.4, 90.2 +/- 8.6 macrophages (AM) on days 1, 5 and 10 respectively compared to controls 2.8 +/- 2.3 (PMN) and 37.2 +/- 1.1 (AM). Analysis of protein (mg/ml BAL fluid) demonstrated a significant increase on exposure for days 5 and 10 (0.8 +/- 0.05 and 0.9 +/- 0.6 respectively versus controls, 0.09 + 0.01, p < 0.01). CONCLUSION: Acute exposure to CDE causes influx into the air spaces of inflammatory leukocytes accompanied by an increase in lung permeability (evidenced by the presence of protein in BAL fluid). In cotton mill workers, the above factors may contribute to the development of chronic byssinosis by as yet undefined agent(s) in cotton dust.

Animals↗

[Genetic improvement of cotton varieties in Huang-Huai region in China since 1950's. III. Improvement on agronomy properties, disease resistance and stability].

Data from a set of 5-location and 2-year experiments on 10 representative historical cotton varieties and the data of Huang-Huai Regional Cotton Trials from 1973 to 1996 were analyzed to estimate the effects of genetic improvement in agronomy properties, disease resistance and stability of cotton in Huang-Huai Region in China. The results indicated that a great genetic progress of earliness and disease resistance had been achieved by breeding programs since 1950's. The maturity was shortened 3-5 days; The rate of preforst yield was increased about 7 percentages. The problem of resistance to Fususium wilt has been solved and the resistance to Verticillum wilt was improving. Some progress in stability of cotton varieties also has been achieved by breeding programs since 1950.

China↗

Genetic diversity evaluation of some Chinese elite cotton varieties with RAPD markers.

RAPDs analysis was used to assess the genetic diversity of some elite cotton varieties. 17 cotton varieties or breeding lines were screened with 200 arbitrary primers to generate 113 polymorphic bands. Cluster analysis and UPGMA showed that 17 varieties could be put into 3 clusters corresponding to genome difference. The genetic similarity among them ranged from 0.2000 to 0.8451. Three elite varieties Ejing-1, Sumian-3 and Zhongmiansuo-12 are highly similar in genetic base. 7581, an offspring from Gossypium hirsutum x G. hirsutum race Latifolium, is distinct from other upland cotton varieties. A trend in germplasm usage in the same research center was also shown in the study. To sustain progress in genetic improvement, we suggest that some good gene from other species should be considered in the upland cotton breeding procedure.

China↗

[Development and expression process of inheritance of resistance to cotton worm (Prodenia litura) in soybeans].

Cotton worm [Prodenia litura(Fabricius)] was one of the major leaf-feeders for soybeans in Southern China. Resistance to leaf-feeders has been recognized as one of the major breeding target traits in the National Soybean Breeding Program. This paper deals with the study of inheritance of resistance of soybeans to cotton worm [Prodenia litura(Fabricius)]. P1, P2, F1, F2, F2:3 of four susceptible x resistant crosses, i.e. N21297 x N1178-2-2, N21266 x N23860, N119-1 x N1178-2-2 and N21266 x N3039, were used in the study. The materials were planted in net room under artificial infestation in 1996-1998. The data of defoliation percentage of successive development stages, during cotton worm damage period were obtained and collected for genetic analysis. The segregation analysis methods for major genes plus polygene mixed inheritance model developed by Gai et al. were used to identify the genetic system of resistance. The results from joint analyses of multiple segregating generations as well as from analyses of single F2 or F2:3 generations of the four crosses showed a two major genes plus polygene mixed inheritance model at fully developed stages of resistance while one or two major genes with or without polygene were observed at other stages. Between the two major genes, the additive effect of one locus was from 1.56 to 9.89(%, defoliation), another from -3.79 to 3.75(%, defoliation). The heritability values of major genes were estimated as 70.40%-99.21%, greater than those of polygene which were only 0.00%-22.29%. Therefore, in the improvement of resistance to cotton worm, major gene resistance should be considered at first.

Animals↗

[Genetic diversity detected by DNA markers and phenotypes in Upland cotton].

Genetic diversity of Upland cotton (Gossypium hirsutum L.) cultivars was evaluated by SSR, ISSR, and RAPD. The genomic DNAs of 36 domestic and exotic cultivars were amplified with 81 SSR primer pairs; 7 ISSR primers and 53 RAPD primers, which yielded 282 polymorphic bands. The range of pair similarity coefficient (Nei, M. And W. Li 1979) between cultivars is from 0.5745 to 0.9291. The result indicated that although the present cultivars have genetic variation to a certain extent, the genetic basis of them is relatively narrow, and it is essential to find some new germplasm for the development of new cultivars. As expected, the classification of the cotton cultivars using the Unweighted Pair-group Method with Arithmetic Average based on the pair similarity coefficients is mostly consistent with known pedigree information and breeding experience. The 36 cotton cultivars have been mainly classed into exotic cultivar group, Chinese Xinjiang ecological region cultivar group, early-mature domestic cutivar group and mediate-mature domestic cultivar group. Carmen and Colorado cultivars from Spain have the lowest similarity with other cultivars, while TM-1 (genetic standard line), MD5lne and PD9364 cultivars from American have higher similarity with domestic cultivars. The reason may be that the parents of the domestic cultivars were mainly introduced from America. However, clusters of domestic cultivars are not all in accordance with their ecological regions, which may result from the pedigree complexity of the cultivars. Meanwhile the genetic diversity of 36 cultivars was investigated at phenotypic level with agronomic and fiber quality traits in the field experiments in 1999 and 2000, and was measured by Euclidean distance on the genotypes. Although grouping result of cluster analysis based on the Euclidean distance is similar than that of molecular data with a significant negative correlation of -0.3350 between the pair similarity coefficients and the Euclidean distance, the subgroup classification of the two methods gives different result. The molecular markers can be effectively applied in classifying cultivars within the group. The study provides useful information for the selection of parents in the development of cotton cultivars and hybrids as well.

Cluster Analysis↗

[Arthropod community structures in transgenic Bt cotton fields].

Arthropod community structures were investigated in transgenic Bt cultivars, Bollgard(B) and Chinese cotton 30 (CC30), and common cultivars, control (C) and no control (NC) cotton field in North China in 1998. The results showed that compared with common cultivars, the species richness and the number of total individual of arthropod community in transgenic Bt cultivars field were reduced 2.4-16.3% and 71.0-78.3% respectively, in which dominant species in phytophagous subcommunity varied. The number of individual of predatory and parastic subcommunity were all increased. The similarity coefficient between CC30 and NC was 0.8243, B and NC 0.7320, B and C 0.3380, C and NC 0.3128, CC30 and C 0.2665. The order of diversity and evenness value of these were CC30 (2.3712 and 0.6428), NC (2.3654 and 0.6251), B (2.1364 and 0.5791), and C (1.0877 and 0.2949), their dominant value was 0.8726 (C), 0.3528(B), 0.1178(NC) and 0.1048 (CC30) respectively. It was concluded that different integrated pest management (IPM) strategy should be implemented in transgenic Bt cotton instead of common variety cotton field.

Animals↗

[Cloning and characterization of D-113 gene promoter from cotton].

To study the expression of late embryogenesis abundant gene in seeds, the 1,024 bp 5' flanking sequence of D-113 gene, a late embryogenesis abundant gene of Gossypium hirsutum cv. Coker 312, was cloned by PCR. The similarity compared with the sequence of Lea protein gene family published was 92.50%. There are three putative ABREs and one enhancer-like which riches A/T in the promoter. The promoter was fused to the beta-glucuronidase gene to form pLD II. Via a particle bombardment, pLD II was introduced into embryogenic calli of cotton and seeds of Brassica napus which were all treated with abscisic acid for 3d before bombardment, also into roots, stems and leafs of cotton. Transient expression was measured histochemically as spot number 24 h after bombardment. GUS sexpression was observed in the seeds of Brassica napus and the embryogenic calli of cotton, but not found in roots and leaves of cotton. Those results indicated that the expression of D-113 gene promoter was embryo specific.

Base Sequence↗

[Sequence analysis of Bt insertion flanking fragments in transgenic Bt cotton].

The copies of outside gene and DNA structure of integration locus are important in high expression and avoidance of gene silence. Many research results showed that outside genes were inserted into the plant genome with recombinant type, and the integration was related to border T-DNA sequence in the course of Agrobaterium mediated transformation. SAR structure was also found in the integration location of transformants with direct DNA transformation method. The pollen-tube pathway transformation, one of direct DNA transformation method, was very successfully used in Bt transgenic cotton in China. But until now there has been no report about Bt gene integration. The aim of this research was to investigate flanking DNA structure in order to explain the mechanism of direct transformation method in the future. The structure of flanking DNA fragments of Bt integration in four different transgenic Bt cotton varieties including Simian-3, 161 resistant breeding line, 161 sensitive breeding line and Guokangmian-1 was analyzed with TAIL-PCR and nested PCR. The flanking DNA sequences of different self-crossed progenies from one plant are the same. In contrary, their DNA sequences are diverse for different breeding lines. Upstream flanking fragments in some transgenic cotton contained short transformation plasmid sequences, downstream flanking fragments in all the transgenic cotton varieties were composed of high percentage AT. The percentage of AT in Simian-3 transgenic Bt variety was as high as 92%. All the flanking fragments were of multi-copies and similar to repetitive sequences. No recognition sites of TOP enzyme were found in these fragments.

Animals↗

[Ecophysiological characteristics and productivity of wheat-cotton community].

The eco-physiology and productivity of 6-2-2 wheat-early maturing cotton-middle maturing cotton were studied in comparison with traditional 6-2 wheat-middel maturing cotton. The results showed that after wheat harvested, the LAI of cotton increased fast, the leaf area duration(LAD) and CGR were raised obviously, the dry matter rose rapidly, and the accumulated amount was larger than CK. Light use efficiency was 1.13%, 21% more than CK. The effective blossom period was extended 18 d, and the lint yield in both 1998 and 1999 was over 2250 kg.hm-2, 21-22% more than CK.

Crops, Agricultural↗