Showing papers on "Lathyrus published in 1969"

Chromosome counts of some Mongolian plants

Abstract: The paper gives the chromosome numbers of 45 species from 72 Mongolian localities, belonging to the genera:Amygdalus, Asparagus, Astragalus, Cancrinia, Caragana, Chamaerhodos, Chelidonium, Chesneya, Dianthus, Hypecoum, Lathyrus, Lilium, Oxytropis, Papaver, Potentilla, Schizonepeta, Sibbaldia, Thermopsis, Trifolium, Trigonella, Vicia. Chromosome morphology of three species ofChamaerhodos and taxonomical remarks on some other species are added. A new combinationSibbaldia sericea (Grubov) Sojak is proposed.

Cross-inoculation experiments with conidia and ascospores of Erysiphe polygoni on pea and other hosts

Abstract: Leaf disks and greenhouse plants of pea (Pisum sativum L., cv. Onward) were inoculated with conidia and ascospores of Erysiphe polygoni DC. from a range of hosts; conidia from pea were similarly transferred to some of these hosts. The development of germinating conidia and ascospores into mildew colonies could be divided into ten stages, and the results of the transfers were assessed in terms of the maximum and most frequent stages of development reached before the mildew growth was arrested. Only conidia from Lathyrus odoratus L. (cult.) produced sporulating mildew colonies on greenhouse pea plants. Conidia from pea produced sporulating colonies on leaf disks but not on L. odoratus. The results are discussed in relation to the epidemiology of pea powdery mildew, particularly the overwintering of the pathogen in England.

Vector Age and Length of Acquisition and Inoculation Access Periods as Factors in Transmission of Pea Enation Mosaic Virus by the Pea Aphid

Abstract: Additional evidence is presented that the transmission of pea enation mosaic virus (PEMV) by pea aphids, Acyrthosiphon pisum (Harris), from and to sweetpea, Lathyrus odoratus L., is most efficiently done by young nymphs, Apparently virus dosage can be varied by alter. ing the acquisition access period, and such variations affect-(1) the number of insects that transmit; (2) the net transmission rate; and (3), to a lesser extent, the period of time that inoculativity is retained. The total number of plants used in virus retention experiments can be reduced by extending the duration of the transfer interval. If such is done, the data indicate that the value of the mean weighted retention period is not markedly changed, although somewhat biased toward a higher value as the interval is lengthened. A similar bias occurs in the estimate of the net transmission rate.

Some properties of pea enation mosaic virus isolated from field pea and broad bean plants in Bohemia

Abstract: Pea enation mosaic virus (PEMV) was isolated from disea sed field pea (Pisum sativum L.ssp. arvense A.Gr.) and broad bean (Faba vulgaris Moench) plants grown as filed crops at Bohumilice in Bohemia. The virus proved to be pathogenic for the following plant species:Pisum sativum L. cv. Raman,Faba vulgaris Moench,Lens culinaris Med.,Vicia sativa L.,Lathyrus odoratus L.,Glycine soja L.,Phaseolus vulgaris L.,Chenopodium amaranticolorCoste andReyn,Nicotiana clevelandiGray,Trifolium incarnatum L. The dilution end point of the isolate was higher in pea plants (10−4) than in broad bean plants (10−2). The thermal inactivation point was 65–68° and the longevityin vitro between 10 and 14 days. According to the host range, symptoms on pea plants and physical properties the virus isolate studied resembles some isolates described in the U.S.A. and represents a PEMV strain different from those reported so far in Czechoslovakia.