Panonychus citri (MacGregor) (Tetranychidae) and Eriophyes medicaginis K. (Eriophyidae): Two important phytophagous mites recorded for the first time in Greece

Panonychus cirri (MacGregor) one of the most important phytophagous mites in many parts of the world, has been collected from citrus trees in various localities of county Preveza, Heperos, Greece. This mite has been, possibly, introduced to Greece via Albania. Another phytophagous mite, Eriophyes medicaginis Keifer, well known to cause witches’ broom on alfalfa, has been collected from Medicago saliva L. in the counties Attiki and Boiotia of central Greece. In a two year study on arthropods associated with alfalfa at the Kopafs region of Boiotia, E. medicaginis was found to be constant and recedent in both years. High population densities were observed during the period mid-September to mid-March.

Studia embriologiczne u pięciu odmian Medicago saliva L. Cz. II [Embriological studies in five varieties of Medicago sativa L. Part II.]

The objective of this study was to elucidate the problem of low seedy yields of five varieties of <i>Medicago sativa</i> L. (Australijska, Grimma, Kleszczewska, Miechowska, and Warmińska) under climatic conditions of northern Poland. The study included pollination and fertilization processes, embryo sac, embryo and endosperm development. These factors in case of lack of the proper amount of pollen, and insufficient number of pollinators, may under certain environmental conditions results in poor seed setting and low fertility of the varieties studied.

Studia nad kariologią i rozwojem pyłku kilku odmian Medicago saliva L. Cz. I [Studies on karyology and pollen development in several varieties of Medicago sativa L. Part I]

At the stage of diakinensis and metaphase of the first meiotic division, conjugating chromosomes in the form of bivalents were always observed. At the pre-meiotic stage some of .the mother pollen cells underwent degeneration (in 'Australian' var. 17% in 'Warminska' 20%, in 'Kleszczewska' 23%, in 'Grimma' 30% and in 'Miechowska' 40%). In the degenerating mother pollen cells no meiotic division were observed. In the surviving mother pollen cells, meiotic division were found to be normal. The mature pollen grains were trinucleate.

AC Blue J alfalfa

AC Blue J alfalfa (Medicago saliva L.) was developed by the Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alberta. This verticillium wilt and bacterial wilt resistant cultivar outyielded Beaver by about 8% in 4-yr trials and 15% in 7-yr trials in western Canada. It is well suited for hay production, dehydration, and silage in areas where verticillium wilt reduces alfalfa yield and stand life. Key words: Cultivar description, alfalfa, Medicago sativa

Study of the phytoestrogen content of goat’s rue (Galega orientalis), alfalfa (Medicago sutiva) and white clover (Trifolium repens)

Studies were conducted to determine the phytoestrogen content of goat’s rue (Galega orientalis Lam.), alfalfa (Medicago saliva L.) and white clover (Trifolium repens L.), all belonging to the Fabaceae family subjected to test cultivation at research stations of the Agricultural Research Centre of Finland. Apart from some insignificant quantities, goat’s rue did not contain any known phytoestrogens. Even in biological studies it had no estrogenic effect. The estrogenic effect of alfalfa was apparently due to coumestrol, which was discovered in the samples in quantities of 34-65 ppm. All white clover varieties contained very small quantities of estrogenic isoflavones and coumestrol, and they did not explain the increased weight of the immature rat uterus observed in the biological studies.

Monosporascus cannonballus. [Descriptions of Fungi and Bacteria].

A description is provided for Monosporascus cannonballus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Cumumis melo, C. sativus,? Medicago saliva, Trifolium pratense. DISEASE: Root rot of melon. GEOGRAPHICAL DISTRIBUTION: India, Japan, USA (Arizona).

Acrocalymma medicaginis. [Descriptions of Fungi and Bacteria].

A description is provided for Acrocalymma medicaginis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOST: Medicago sativa (Lucerne). DISEASE: Root and crown rot of Medicago saliva. Affected plants show a reddish flecking in the cortex and vascular tissues of crowns and roots and the bark in infected areas is often fissured. As the disease advances, dry rot develops and the older infected tissues turn black. GEOGRAPHICAL DISTRIBUTION: Australia (New South Wales, Queensland, South Australia). TRANSMISSION: Most probably through soil and by water dispersed conidia.

A COMPARISON OF STABILITY METHODS TO ASSESS ALFALFA POPULATIONS FOR PERFORMANCE FOLLOWING FREEZING STRESS

To develop cultivars with greater tolerance to environmental stresses, an accurate assessment and ranking of experimental strains for stress environments is essential. This study was conducted to compare the regression, genotype mean — CV grouping, and superiority measure approaches for rating 16 alfalfa (Medicago saliva L.) populations for performance following freezing stress. Field-grown plants were excavated in November, subjected to a range of freezing stresses (−8 to −16 °C), and regrowth yield measured. Two plant ages (seeding year and first production) over 2-yr were assessed. The three stability analyses investigated did not give the same ranking of regrowth performance among the 16 alfalfa populations. The superiority index and mean–CV grouping techniques were better in detecting populations that performed well over the range of freezing stress compared with the regression method. The superiority index provided a continuous ranking index of entries which would be useful for selection applications; however, it has a potential bias towards more responsive entries in low stress environments. For selection purposes, the superiority index should be combined with a regression analysis.Key words: Alfalfa, Medicago sativa L., freezing stress, genotype × environment interaction, stability assessment.

Involvement of the solid phase of rumen digesta in the interaction between copper, molybdenum and sulphur in sheep

1. Merino sheep fed on a diet of chopped wheaten hay, chopped lucerne (Medicago saliva) hay and oat grain were the source of rumen contents for the study. The diet contained (mg/kg dry weight) 3.3 copper, 0.24 molybdenum and 2.8 sulphur. The effects of adding between 5 and 25 mg Mo/kg as ammonium molybdate (AM) or tetrathiomolybdate (TTM) on the distribution and forms of Cu and Mo in rumen contents were investigated in vivo and in vitro.2. Approximately 88 % of the Cu and 94% of the Mo in rumen contents were associated with the solid phase. When AM or TTM was added to rumen contents in vivo or in vitro the proportion of these elements in the solid phase was increased at the expense of the fluid phase.3. The addition of AM and TTM to rumen contents also decreased the proportion of Cu that was soluble in trichloroacetic acid (50 g/l; TCA) and increased the proportion of Cu that was not extractable by sequential treatment with TCA and neutral detergent.4. Column chromatography of neutral-detergent extracts of rumen contents revealed that TTM treatment caused Cu to be strongly bound to proteins of high molecular weight.5. Addition of sulphide to rumen contents did not result in significant changes in the distribution of Cu between the fluid and solid phases, or in the solubility of Cu in TCA.6. It is postulated that constant removal of TTM from the fluid phase via reaction with proteins and other macromolecules in the solid phase results in greater formation of TTM in vivo than would be expected from solution chemistry. The molybdo-proteins so formed are strong chelators of Cu and may be the agents responsible for the decrease in Cu absorption in animals that consume diets containing high concentrations of Mo.

Cylindrocarpon olidum var. olidum. [Descriptions of Fungi and Bacteria].

A description is provided for Cylindrocarpon olidum var. olidum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Wide range. At IMI there are records on: Asparagus, Camellia, Cocos, Cordylina, Heterodera (nematode), Medicago saliva, Narcissus, Pelargonium, Picea, Pinus, Pyrus, Secale, Solanum.DISEASE: Root rotting. GEOGRAPHICAL DISTRIBUTION: Africa: Ghana, Zimbabwe; Australasia: Australia; Europe: Germany, Great Britain; North America: Canada, Honduras, USA. TRANSMISSION: Soil-borne; slimy spores are probably spread by water.