Comparative Study for the Relative Importance of Characters Contributing to Seed-Cotton Yield in American and Egyptian Cottons

The path coefficient analysis was employed to determine the contribution of boll number per plant, boll weight and seed index characters to the variation in seed-cotton yield per plant, in the American and Egyptian cotton varieties; McNair 220 and Giza 75 respectively. Data obtained from yield trials carried out at Fayoum Experimental Farm, Faculty of Agriculture, in two growing seasons, 1982 and 1983, were used in this analysis.
It was found that boll number per plant had the greatest contribution to seed cotton yield in both American and Egyptian cotton varieties. Selection for number of bolls/plant and boll weight in American Upland cotton accounts for about 75% of the yield. While in Egyptian cotton, number of bolls/plant and boll weight account for about 60% only of yield.
The arrangement of the components contributing to plant yield, according to their relative importance in McNair 220 variety was:
(1) The direct effect of bolls/plant. (2) The direct effect of boll weight. (3) The joint effect of number of bolls with boll weight. While in Giza 75 variety the arrangement was as follows:
(1) The direct effect of number of bolls per plant. (2) The joint effect of number of bolls with boll weight. (3) The direct effect of boll weight.     

Synergism of teflubenzuron and chlorfluazuron in an acylurea-resistant field strain of Plutella xylostella L. (lepidoptera: Yponomeutidae)

Topical application of the synergists piperonyl butoxide (PB) and S,S,S-tributyl phosphorotrithioate (DEF) to second-instar larvae of a standard laboratory strain (FS) and an unselected Malaysian field strain (CH) of the diamondback moth Plutella xylostella had no significant effect on the toxicity of the acylurea insecticides, chlorfluazuron and teflubenzuron, in a subsequent leafdip bioassay. In contrast, pre-treatment with PB or DEF in acylurea-selected subpopulations of the CH strain with varying levels of cross-resistance to chlorfluazuron and teflubenzuron significantly increased (up to 34-fold and 28-fold, respectively) the toxicity of both compounds, suggesting that microsomal monooxygenases and esterases may be involved in resistance. The addition of a mineral oil, ‘Sunspray 6E’, to topically-applied chlorfluazuron consistently reduced its LD₅₀ value, and the effect of the oil appeared to be greatest on the most resistant population of P. xylostella. However, the effects of the oil were not significant (P > 0·05) and further studies are necessary to determine whether a penetration factor is present in the CH strain.     

Cross-resistance between acylurea insect growth regulators in a strain of Plutella xylostella L. (Lepidoptera: Yponomeutidae) from Malaysia

The activities of the acylurea insect growth regulators, chlorfluazuron, teflubenzuron and difubenzuron, and the neurotoxic macrocyclic lactone, abamectin were assessed against a laboratory susceptible (FS) strain and a field (Cameron Highlands, Malaysia (CH)) strain of the diamondback moth, Plutella xylostella L. using a leaf-dip bioassay at 20°C. The time taken to achieve end-point mortality was found to vary considerably (9–17 days), being fastest with abamectin against the FS strain and slowest with difubenzuron against the CH strain. The order of activity (LC₅₀ at F6/7) against second-instar larvae of both strains was: abamectin > chlorfluazuron = teflubenzuron ? difubenzuron. Subsequent assays (F14) with the acylureas, flufenoxuron and hexaflumuron against the FS strain suggested that the former was slightly more active than chlorfluazuron or teflubenzuron, the latter slightly less active. The CH population was found to be 12.6-, 6.7-, 6.4- and 2.3-fold less sensitive to difubenzuron, teflubenzuron, chlorfluazuron and abamectin respectively than the FS strain. Selection of sub-populations of the CH strain with chlorfluazuron (CHL-SEL) and teflubenzuron (TEF-SEL) for six generations (F6-11), resulted in LC₅₀ resistance ratios of 109- and 315-fold respectively when compared with the FS strain, equivalent to an 18- and a 46-fold increase in resistance compared with the unselected CH strain. Marked cross-resistance was also demonstrated between chlorfluazuron and teflubenzuron in both sub-populations. However, there was no evidence of cross-resistance to dijlubenzuron and abamectin and little or no cross-resistance to flufenoxuron and hexaflumuron. Resistance to chlorfluazuron and teflubenzuron appeared to be relatively unstable in the TEF-SEL compared with the CHL-SEL sub-population (over 6–9 generations). However, reselection of the TEF-SEL population with chlorfluazuron (F18–20) led to a very rapid increase in resistance to chlorfluazuron and particularly teflubenzuron. For the latter compound, resistance factors of about 1000000 were obtained (F19, 21). Such values are probably only semi-quantitative, as above a certain level of resistance feeding bioassays with acylureas (compounds which are active to a significant extent by ingestion) are likely to become rate-limiting.     

Genetic Advances in Adapting Rice to a Rapidly Changing Climate

Rice, with its wide geographic distribution extending from 50°N to 35°S, is expected to be the most vulnerable cultivated crop to future changing climates. Among the different abiotic stresses, extreme temperatures coinciding with critical developmental stages, increasingly frequent floods and drought spells, and worsening sea water inundation are some of the major threats to sustainable rice productivity. Following the successful implementation of molecular marker‐assisted backcrossing to introgress large‐effect QTL for submergence tolerance in rice mega varieties, rice breeding for drought, salinity and, recently, heat tolerance is employing the same approach. Although tolerance for combined submergence and salinity has been achieved, developing rice varieties with multiple tolerance for other abiotic and biotic stresses and finding the appropriate agronomic package to exploit their performance remain a challenge. The major bottleneck is the lack of unidentified large‐effect QTL for other abiotic stresses that are strongly influenced by genotype × environment (G × E) interaction. Rapid advances in the use of molecular tools, including a plethora of SNP markers, are expected to facilitate the development of major abiotic stress‐tolerant rice. In response to the actual farmer field situation, progress achieved in understanding and developing independent abiotic stress tolerance is being exploited to combine tolerances (for example, heat and drought; salinity and submergence) to address emerging environmental problems across a wide range of rice ecosystems.     

Pathological changes,distribution and detection of Brucella melitensis in foetuses of experimentally-infected does

BackgroundBrucellosis of goats is caused by Brucella melitensis. It is a re-emerging zoonotic disease in many countries due to transmission from domestic animals and wildlife such as ibex, deer and wild buffaloes.ObjectiveTo describe the pathological changes, identification and distribution of B. melitensis in foetuses of experimentally infected does.MethodsTwelve female goats of approximately 90 days pregnant were divided into 4 groups. Group 1 was exposed intra-conjunctival to 100 µL of sterile PBS while goats of Groups 2, 3 and 4 were similarly exposed to 100 µL of an inoculum containing 10⁹ CFU/mL of live B. melitensis. Goats of these groups were killed at 15, 30 and 60 days post-inoculation, respectively. Foetal fluid and tissues were collected for bacterial identification (using direct bacterial culture, PCR and immuno-peroxidase staining) and histopathological examination.ResultsBilateral intra-conjunctival exposure of pregnant does resulted in in-utero infection of the foetuses. All full-term foetuses of group 4 were either aborted or stillborn, showing petechiations of the skin or absence of hair coat with subcutaneous oedema. The internal organs showed most severe lesions. Immune-peroxidase staining revealed antigen distribution in all organs that became most extensive in group 4. Brucella melitensis was successfully isolated from the stomach content, foetal fluid and various other organs.ConclusionVertical transmission of caprine brucellosis was evident causing mild to moderate lesions in different organs. The samples of choice for isolation and identification of B. melitensis are stomach content as well as liver and spleen tissue.     

Leveling-index based variable rate seeding technique for paddy

Precision Agriculture - Poor land leveling of paddy fields leads to irrigation problems which affect crop establishment and ultimately yield. One way to manage this is to vary the seeding rate...     

Anatomic investigation of the lumbosacral plexus of the helmeted guinea fowl (Numida meleagris)

The study was conducted for the determination of the main nerves of the lumbosacral plexus in the helmeted guineafowl. Five helmeted guineafowls were used. Fowls were anaesthetised and the a. carotis communis was cut for blood drainage. Body cavities were revealed and were fixated with 10% formaldehyde. Nerves forming the lumbosacral plexus were dissected and photographed. Results were named according to the Nomina Anatomica Avium. It was determined that the lumbosacral plexus forms by 8 synsacral ventral rami from the ventrolateral side of synsacrum which include (2–9) synsacral spinal nerves. It was seen that the lumbar plexus was formed by the ventral rami of the 2nd, 3rd and 4th spinal nerves, and the sacral plexus was formed by the ventral rami of the 5th, 6th, 7th, 8th and 9th synsacral spinal nerves. It was observed that following nerves of n. pubicus (ilioinguinalis), r. cutaneous femoris lateralis, r. cutaneous femoris medialis (n. saphenus), n. femoralis and n. obturatorius originate from the lumbar plexus, and following nerves of n. ischiadicus, the common branch of n. fibularis and n. tibialis originate from the sacral plexus. It was determined that the n. ischiadicus was formed by the truncus cranialis, medianus and caudalis. In conclusion, it was determined that there are macro anatomical differences between different avian species in the quantity, thickness and distribution of the spinal nerves that form the lumbosacral plexus, and in formations of the plexus, and in separations of nerve branches.     

Improving food provision in a Guyanese home for the elderly: a participatory approach

OBJECTIVES: To conduct a needs assessment of all aspects of food provision in a residential home and to evaluate a subsequent nutrition intervention. DESIGN: An intervention study using a before and after design. A participatory approach was adopted and quantitative and qualitative methods used throughout. The intervention involved a revised menu, kitchen equipment, and establishing wholesale shopping and food donations. SETTING: A residential home for senior citizens in Guyana. RESULTS: Meals at the home were nutritionally inadequate and deeply unpopular with the residents. Intakes of fruits and vegetables were low and the home was heavily reliant on donated soya mince and rice. Meals were served within an eight-hour period to accommodate the staff's hours of work. Cutbacks in the food budget indicated that the financial state of the home explained some of the problems. The intervention was unable to address all problems identified, but led to substantial improvements in the nutritional adequacy of the food provided following the inclusion in the menu of a number of nutrient-dense foods such as chicken liver. The new menu was acceptable to the cooks and largely popular with the residents, although some problems persisted. CONCLUSIONS: The results show that improvements in the nutrient profile of the diet could be achieved with a flexible, community-based, participatory approach that addressed all elements of a home's food provision system. The changes also proved largely popular with the residents, thus potentially contributing to their quality of life.     

Peritoneal fluid analysis in adult, nonpregnant Awassi sheep

BACKGROUND: To the authors' knowledge, there is no information in the literature about normal peritoneal fluid values in ovine species. OBJECTIVES: The purpose of the study reported here was to establish reference intervals for peritoneal fluid from clinically normal Awassi sheep and to compare the values to those in blood. METHODS: Peritoneal fluid and blood samples were collected into tubes containing EDTA, from 40 clinically healthy, nonpregnant, female Awassi sheep, aged 2 to 7 years. Total nucleated cell count (TNCC) was determined using an electronic cell counter. Total protein, albumin, urea, creatinine, and glucose concentrations and aspartate transaminase activity were analyzed using commercially available kits. RESULTS: TNCC (mean +/- SD) of peritoneal fluid was 1.1 +/- 0.87 X 10(3)/microl, with neutrophils (3.9%), lymphocytes (33.5%), macrophages/monocytes (61.2%), and eosinophils (1.4%). Biochemical results in peritoneal fluid were: total protein, 1.7 +/- 0.74 g/dL; albumin, 1.0 +/- 0.04 g/dL; urea, 12.6 +/- 3.95 mg/dL; creatinine, 0.6 +/- 0.19 mg/dL; glucose, 54.8 +/- 6.11 mg/dL; and aspartate transaminase, 23.5 +/- 8.82 U/L. Eosinophil percentage and creatinine concentration did not differ significantly from blood values. CONCLUSION: Baseline values for cytologic and biochemical parameters in peritoneal fluid of Awassi sheep, with comparison to blood, have been generated. Such data may be applicable to other ovine species and can be used in the clinical investigation of ovine abdominal disorders.