SSR markers for marker assisted selection of root-knot nematode (<Emphasis Type="Italic">Meloidogyne incognita</Emphasis>) resistant plants in cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis> L)

Cotton (Gossypium hirsutum L) cultivars highly resistant to the southern root-knot nematode (RKN) [Meloidogyne incognita (Kofoid and White) Chitwood] are not available. Resistant germplasm lines are available; however, the difficulty of selecting true breeding lines has hindered applied breeding and no highly resistant cultivars are available to growers. Recently, molecular markers on chromosomes 11 and 14 have been associated with RKN resistance, thus opening the way for marker assisted selection (MAS) in applied breeding. Our study aimed to determine the utility of these markers for MAS. Cross one was RKN resistant germplasm M240 RNR × the susceptible cultivar, FM966 and is representative of the initial cross a breeder would make to develop a RKN resistant cultivar. Cross two consists of Clevewilt 6 × Mexico Wild (PI563649), which are the two lines originally used to develop the first highly RKN resistant germplasm. Mexico Wild is photoperiodic. We phenotyped the F₂ of cross one for gall index and number of RKN eggs per plant and genotyped each plant for CIR 316 (chromosome 11) and BNL 3661 (chromosome 14). From this, we verified that MAS was effective, and the QTL on chromosome 14 was primarily associated with a dominant RKN resistance gene affecting reproduction. In the first F₂ population of cross two, we used MAS to identify 11 plants homozygous for the markers on chromosomes 11 and 14, and which also flowered in long days. Progeny of these 11 plants were phenotyped for RKN gall index and egg number and confirmed as RKN highly resistant plants. Generally about 7–10 generations of RKN phenotyping and progeny testing were required to develop the original RKN highly resistant germplasms. Our results show that commercial breeders should be able to use the markers in MAS to rapidly develop RKN resistant cultivars.     

Validation and application of a high fidelity mRNA linear amplification procedure for profiling gene expression

The need for microgram quantities of RNA for microarray experiments has hindered application of this novel technology in cell types/tissue samples with limited abundance of RNA. In this study, potential application of T7-based linear RNA amplification was investigated for use in gene expression profiling experiments where starting material is limited. Yield and integrity of amplified antisense RNA (aaRNA), microarray hybridization intensities, and fidelity of differential gene expression detected were determined for arrays generated for unamplified versus amplified RNA from the same homogenous starting pools. Total RNA was extracted from bovine spleen and fetal ovary, serially diluted to concentrations ranging from 2 microg to 500 pg and amplified. Quality and quantity of total input RNA and aaRNA were assessed by spectrophotometry, gel electrophoresis and bioanalyzer. In experiment 1, we determined the optimal amounts of aaRNA generated from 20, 40, 200 ng and 2 microg input total RNA for use in cDNA synthesis, labeling and array hybridization that would yield robust and consistent hybridization signals on a bovine oocyte cDNA microarray. In experiment 2, comparison of microarray hybridization intensities and fidelity of differential gene expression between aaRNA generated from 2, 20 and 40 ng input total RNA versus unamplified RNA (uRNA) were conducted. The hybridization intensities for each of the 7000 spots per slide for microarrays conducted using aaRNA versus uRNA were highly correlated (2 ng = 0.84, 20 ng = 0.88, 40 ng = 0.90; P < 0.01). The false positive rate was low and similar (4.0% versus 4.4%) for arrays done with uRNA and aaRNA. Ninety-seven ESTs were detected as differentially expressed in the fetal ovary versus spleen at > 1.5- or < 0.5-fold using uRNA (P < 0.05). However, the number of genes detected in arrays using aaRNA was approximately 1.5-2.5 times greater than with uRNA. Approximately, 65-70% of differentially expressed genes were common between uRNA and aaRNA arrays. Relative fold-expression (Cy3/Cy5 ratios) for 25 overlapping abundant genes was comparable for uRNA versus aaRNA arrays with 2 and 20 ng total RNA as input. Results demonstrate that T7-based linear amplification of small amounts of input RNA and use of aaRNA in microarray experiments retains fidelity of detection of differential gene expression that is relatively comparable to experiments done with uRNA and provides a potentially viable approach to facilitate gene expression profiling using limited amounts of starting material.     

Passalora blight of anise (Pimpinella anisum) and its control in Turkey

Passalora blight of anise, caused byPassalora malkoffii (Bubák) U. Braun, is an important disease of anise in Turkey. The disease affects all the aboveground parts of plants including flower clusters. Infected seeds have dark, linear stromata. Detection of the pathogen on seeds was studied by the blotter method, agar method, washing test and sowing infected seeds in disease-free soils. The pathogen was recovered only by the washing test and to a limited extent by water agar + seed decoction agar. Sixteen of 24 seed samples from diseased regions were found to be infected. The pathogen was not detected by any other methods. However, several indigenous fungi,e.g. Alternaria alternata, were isolated, which may have prevented the growth of the pathogen. Seed washings of infected seed samples had typical spores of the pathogen up to 10⁶ conidia per gram of seed. Transmission of the pathogen was shown by sowing infected seeds in disease-free field soils in two locations where anise had not been grown previously. Azoxystrobin, chlorothalonil + carbendazim and flutriafol seed treatments at 0.04 g a.i. kg⁻¹ seed, 1.0 g + 4.5 g a.i. kg⁻¹ seed and 0.015 g a.i. kg⁻¹ seed reduced the disease by 92.5%, 89.6% and 36.2% in 2002 and by 78.9%, 75.8% and 41.2% in 2003, respectively. Three foliar applications of axosystrobin, chlorothalonil + carbendazim and flutriafol at the rates of 187.5 g a.i. ha⁻¹, 1500 g + 6750 g a.i. ha⁻¹ and 31.3 g a.i ha⁻¹ reduced disease incidence by 92.5%, 86.0% and 96.8% in 2002 and by 97.5%, 90.8% and 97.0% in 2003, respectively. http://www.phytoparasitica.org posting May 17, 2005.     

Studies on differential response of wheat cultivars to boron toxicity

Experiments were carried out to study the differential responses of different wheat cultivars to boron toxicity in field, greenhouse and growth chamber conditions. In field trials carried out at two locations, both of which are known to contain toxic amounts of water-extractable B, significant correlations were obtained between toxicity symptoms and grain yields. The only durum cultivar included in this group of experiments (Kunduru 1149) was the most sensitive of the 21 cultivars trialed. The most tolerant cultivars were of local origin. Genotype-environment interaction was considerably large. Twenty-nine bread wheat and three durum wheat cultivars were compared in a greenhouse experiment with and without the application of 40 mg L^-1 B. Again, the durums were the most sensitive cultivars. The most tolerant cultivars were either selections from local populations or had at least one parent of local origin. The detrimental effect of B on root dry matter production was much higher than on shoot dry matter (45 and 26%, respectively), but genotypical variation was greater in shoot growth retardation. While this implies the possible role of reduced translocation, high concentrations of B in the shoots of tolerant cultivars (though lower than in the sensitive cultivars) indicated the existence of other contributing mechanisms, such as tissue tolerance. Also, greater genotypical variation in older leaves showed that reduced uptake might be more important than reduced translocation in some cases. Due to the lack of correlation between results from the field and the controlled-environment studies, it was concluded that screenings should be undertaken in both situations as a means of verification. Another conclusion drawn was that symptom scoring for B tolerance was more reliable than measuring plant B concentrations. This revised version was published online in August 2006 with corrections to the Cover Date.     

Feather content of porphyrins in Eurasian eagle owl (Bubo bubo) fledglings depends on body condition and breeding site quality

Porphyrins are pigments produced in most animal cells during the synthesis of heme, but their importance for external coloration is unclear. Owls (Order Strigiformes) are among the few animals that accumulate porphyrins in the integument, where it could serve as a means of signaling. Here we hypothesized that the porphyrin content of feathers may depend on body condition and breeding site quality in Eurasian eagle owl (Bubo bubo) fledglings and, thus, constitute amplifiers of the quality of the area where they are born. Using high‐performance liquid chromatography, we found 2 porphyrins (protoporphyrin IX and coproporphyrin III) in the body feathers of 19 eagle owl fledglings from 7 breeding territories. Coproporphyrin III, but not protoporphyrin IX feather concentration, was positively associated with the body mass of fledglings and with the quality of the breeding sites where they were reared with respect to food quality and availability. As coproporphyrin III is produced under oxidative stress, we suggest that good breeding sites may lead to fledglings in good condition. This, in turn, may make fledglings induce a certain level of free radical and coproporphyrin III production to signal to conspecifics their site‐mediated capacity to cope with oxidative stress. This is the first time that porphyrin content in the integument has been found to be related to individual quality, opening a new scenario for studying evolution of animal coloration.     

Bycatch and discards from two types of bivalve dredges targeting Donax trunculus and Chamelea gallina used in the southern coast of the Marmara Sea,Turkey

Fisheries Science - Intensive commercial harvesting of the wedge clam Donax trunculus and the striped venus Chamelea gallina was conducted along the southern coast of the Marmara Sea using a...     

Evaluation of attract-and-kill strategy for management of cocoa pod borer,Conopomorpha cramerella,in Malaysia cocoa plantation

Abstract

In South-East Asia, cocoa production is dramatically affected by cocoa pod borer (CPB) infestations. As an alternative tool to chemical control, the efficacy of attract-and-kill strategy (CPB sex-pheromone as attractant and Delta trap without sticky liner sprayed with cypermethrin solution as killing station) was evaluated and compared with current standard CPB management approach as control treatment during two main cocoa harvest seasons in Malaysia (with 100 µg and 33.3 µg CPB-pheromone loading per station, respectively). In both seasons, attract-and-kill strategy was highly effective at reducing male flight activity (p?<?0.05) in attract-and-kill plots comparing with standard CPB management plots. For the percentage of CPB-infested pods, the attract-and-kill strategy (100 µg) was as good as the conventional pesticide spray applications of cypermethrin (p?=?0.083) in first season. However, it was significantly (p?=?0.021) reduced in the second season with lower pheromone loading (33.3 µg), indicating that this semiochemical based strategy is far superior to and more feasible than the currently applied conventional synthetic pesticide treatment and is therefore a good alternative in CPB integrated pest management.     

Colostral Transfer of Rinderpest Neutralizing Antibody to Offspring of Våccinated Dams

The transfer of maternal antibodies to Friesian and buffalo calves born of dams vaccinated against rinderpest was through colostrum only. Colostral antibody titers at the time of parturition were higher than the serum titer. Two hours after suckling, a high level of rinderpest neutralizing antibodies was detected in the sera of newborn animals. The half-life of maternal antibodies in buffalo and Friesian calves was found to be approximately 33 and 29 days respectively. By the age of 7-8 months, 60 per cent of buffalo calves and 80 per cent of Friesian calves had no detectable levels of rinderpest neutralizing antibody.