不同地域柳松菇菌株遗传多样性的初步研究

应用同工酶技术和RAPD技术对7个来源于不同地域的柳松菇菌株进行了遗传多样性分析,两种方法的分析 结果基本一致。结果表明,地域差异对柳松菇菌株之间的遗传差异有明显影响,不同地域中分布的柳松菇菌株有丰富的遗传多样性。该研究为柳松菇的杂交亲本选配提供了实验依据,也为进一步研究柳松菇种质资源的遗传多样性提供了方法学上的参考。     

Art, Anteil und Verteilung niedrig molekularer Kohlenhydrate in der Rotbuche (Fagus sylvatica Linn)

Ohne Zusammenfassung     

A test method for resistance to stem mottle in potatoes

In breeding for resistance to stem mottle in potatoes there is a need for a rapid testing and selection method. Following the method normally used with X- and Y-virus, seedlings in the cotyledon stage and young plants of potatoes were inoculated with the stem mottle virus (= rattle virus). In this way it seems possible to test and to select young seedlings for resistance. In addition it is possible to establish rapidly the resistance of known potato varieties and progenitors with the air of young plants.     

The Urinary Excretion of Riboflavin by the Cat

Abstract— The daily riboflavin excretion of five adult cats has been studied for periods ranging from 7 to 11 days. The cats were housed in metabolism cages and were provided with a diet of cooked rabbit meat, wholemeal bread and water. The total amount of riboflavin excreted does not appear to be related to the dietary intake. The concentration of riboflavin in the urine does appear to be characteristic for a given cat under our experimental conditions.
Résumé— L'excrétion quotidienne de riboflavine chez cinq chats adultes a étéétudié pendant des périodes allant de 7 à 11 jours. Les chats étaient casés dans des cages à métabolisme et recevaient un régime de viande de lapin cuite, de pain entier et d'eau. La quantité totale de riboflavine excrétée ne semble pas être en rapport avec la quantité ingérée. Dans les conditions expérimentales que nous avons utilisées la concentration urinaire de riboflavine parait caractéristique pour un chat donné.
Zusammenfassung— In einer von 7 bis zu 11 Tagen reichenden Zeitspanne wurde untersucht, wieviel Laktoflavin fünf ausgewachsene Katzen täglich ausscheiden. Die Katzen wurden in Käfigen untergebracht, in denen der Stoffwechsel ständig überprüft werden kann, und sie wurden mit einer aus gekochtem Kaninchenfleisch, Vollkornbrot und Wasser bestehenden Diät gefüttert. Die Gesamt-menge des ausgeschiedenen Laktoflavins scheint in keiner Beziehung zu der Nahrungsaufnahme zu stehen. Die Konzentration des Laktoflavin im Urin scheint für eine unter unseren Versuchs-bedingungen stehende Katze charakteristisch zu sein.     

The relationship between the rate of fertilizer nitrogen applied to grassland and milk production; an analysis of recorded farm data

The milk yields obtained from 845 herd-years within the ICI Recorded Farms Scheme have been correlated, by multiple regression analysis, with the N fertilizer supplied to the grassland, the quantities of concentrates fed and the stocking rates. The large quantity of data gave highly significant correlations which indicated that, over the whole period, the supply of an extra 1 kg N from fertilizer was associated with an average extra yield of 9·9 1 milk. 4·9 1 were associated with the extra N independently of any simultaneous changes in either stocking rate or concentrate feeding, and 4-5 1 were ascribable to a simultaneous increase in stocking rate. There was a substantial variation in the ‘milk yield per kg N’ response from year to year, but the average value over 6 years agreed closely with that observed in the period 1949–52.     

The assessment of persistence and its application to the evaluation of mid-season and late perennial ryegrass cultivars

Persistence assessments on eight mid-season and ten late cultivars of perennial ryegrass were made at the end of the second, third and fourth years after sowing. Botanical analyses were carried out on the herbage from plots cut in the fourth year and these results related lo the different persistence assessments. It was found that persistence assessments carried out at the end of the second year enabled predictions to be made about botanical composition of cuitivars in the fourth year. Little extra precision was gained by delaying assessment until the third or fourth years as the ranking order of cultivars with respect to persistence remained largely unchanged. All persistence assessments were positively correlated with yields of sown cultivars and negatively correlated with yields of unsown herbage species in the fourth year. However, only low correlation coefficients were obtained between persistence assessments and the total yield of sown cultivar and unsown species in the fourth year, due to yield substitution between these two components. In swards sown as monocultures low persistence in a cultivar is considered to be a lack of perenniality and tiller regeneration rather than poor competitive ability against volunteer species though in mixed swards competitive ability per se will have considerable influence upon the changes in botanical composition under different managements. Persistence and yield capacity are seen, however, as distinct characteristics of a cuitivar and long-term yield potential is a joint function of these characteristics.     

Dalapon resistance at an early seedling stage in Lolium perenne

The inhibitory effect of the herbicide dalapon on germination and shoot elongation was evaluated in two perennial ryegrass cultivars, Melino RvP and Cropper. These cultivars had been shown to be dalapon resistant and susceptible, respectively, in a previous comparison of 14-week-old plants. Dalapon (10^-2 and 10^-3 m) significantly reduced rates of germination and shoot elongation to the same extent in both cultivars. It is suggested that the effects of dalapon on germination and shoot elongation during the first 9 days of development are not indicative of levels of resistance in more mature plants.