Initial fruit set at high temperature in olive,Olea europaea L.

SUMMARY

The effects of temperature on the progamic phase, fertilization and initial fruit set in cross pollinated olives were studied to determine the reasons for poor fruit set when high temperatures occur during the bloom period. Fruit set in ‘Manzanillo’ olive was completely inhibited at 30°C constant temperature. This temperature significantly reduced pollen germination but did not prevent pollen tube growth. Ovule penetration by the pollen tube was observed in 47% of the flowers at 30°C; however, the lack of growth of both functional ovules and ovaries suggests problems in zygote formation or endosperm development. The most favourable temperature was 25°C, in which faster pollen tube growth, more and earlier fertilization, and more fruit set occurred. At 20°C pollen tube growth was slower, resulting in delayed and reduced fertilization.     

Differences in Feeding Sites Induced by Root-Knot Nematodes, Meloidogyne spp., in Chickpea

ABSTRACT Root-knot nematodes (Meloidogyne spp.) are sedentary, obligate endoparasites in plants, where they induce specialized feeding sites. The feeding sites act as strong metabolic sinks to which photosynthates are mobilized. The histopathological modifications in the nematode-induced feeding sites of artificially inoculated chickpea cv. UC 27 were qualitatively and quantitatively compared using five isolates of M. artiellia and one isolate each of M. arenaria, M. incognita, and M. javanica. All Meloidogyne isolates infected chickpea plants, but root gall thickening was significantly less for M. artiellia isolates than for the other Meloidogyne species. Nevertheless, neither the number of giant cells in the feeding site (averaging four to six) nor the area of individual giant cells was influenced by nematode species or isolate. However, the number of nuclei per giant cell was significantly smaller, and the maximum diameters of nuclei and nucleoli were significantly greater, in giant cells induced by M. artiellia isolates than in those induced by M. arenaria, M. incognita, or M. javanica. In a second experiment, M. artiellia-induced giant cells in faba bean and rapeseed also contained a small number of large nuclei.     

Population evaluation in crop wild relatives for <Emphasis Type="Italic">in situ</Emphasis> conservation: a case study for raspberry <Emphasis Type="Italic">Rubus idaeus</Emphasis> L. in the Leningrad region,Russia

Many crop wild relatives are usually widely distributed species, and in this relation a question arises about selecting populations of special importance for conservation. Using Rubus idaeus as an example, we propose a compound selection of wild populations for in situ conservation. Twelve raspberry populations in the Leningrad region have been evaluated from the point of view of their significance for in situ conservation. To exclude the run-wild forms from the evaluation process, we tried to identify them applying a mathematical model developed by statusmetry method. The constructed model is based on morphological features of leaves of primocanes and helps to distinguish the wild forms from the cultivated and run-wild ones. The wild raspberry populations were screened for plants with features useful for cultivated raspberry improvement such as waxy cover presence, yellow fruiting plants, spinelessness, fruiting primocanes and others. The diversity of wild raspberry populations was assessed by variation of morphological features, presence of botanical varieties and polymorphism of seed storage proteins. The results of viability status assessment for the chosen populations reflect the perspectives of their development and permit to determine the strategy and measures for optimal conservation.     

Presumptive herpesvirus-associated erythema multiforme in a cat

Erythema multiforme (EM), an uncommon immune-mediated skin disorder of cats, conceivably could be triggered by feline herpesvirus type-1 (FHV-1) infection, in a manner analogous to human herpesvirus-associated EM (HAEM). This report describes a 10-year-old Persian-mixed cat with a presumptive diagnosis of HAEM.     

Differences in ovary size among olive (Olea europaea L.) cultivars are mainly related to cell number,not to cell size

Differences in mature fruit size among olive cultivars are related to differences in ovary size at bloom, but it is not known whether cell number or size determines the variation in ovary size. In this study we measured cell size and number in equatorial cross-sectional areas of the principal ovary tissues (mesocarp and endocarp) in eight cultivars with very different fruit and ovary size. The results showed that cell number explained most of the differences in ovary size, while cell size was not related to ovary size, except for a weak (R² = 0.33) correlation in the endocarp. Since sink strength is thought to be related to cell number, this finding supports the hypothesis that larger ovaries represent stronger sinks. The implications of greater sink strength with bigger ovaries are discussed. Within cultivars, while the cross-sectional areas of mesocarp and endocarp were similar, cell number was higher in the mesocarp but cell size was smaller compared to the endocarp.     

Activation of aldehyde dehydrogenase-2 reduces ischemic damage to the heart

There is substantial interest in the development of drugs that limit the extent of ischemia-induced cardiac damage caused by myocardial infarction or by certain surgical procedures. Here, using an unbiased proteomic search, we identified mitochondrial aldehyde dehydrogenase 2 (ALDH2) as an enzyme whose activation correlates with reduced ischemic heart damage in rodent models. A high-throughput screen yielded a small-molecule activator of ALDH2 (Alda-1) that, when administered to rats before an ischemic event, reduced infarct size by 60%, most likely through its inhibitory effect on the formation of cytotoxic aldehydes. In vitro, Alda-1 was a particularly effective activator of ALDH2*2, an inactive mutant form of the enzyme that is found in 40% of East Asian populations. Thus, pharmacologic enhancement of ALDH2 activity may be useful for patients with wild-type or mutant ALDH2 who are subjected to cardiac ischemia, such as during coronary bypass surgery.