This paper presents the chromosome numbers (2n) for 13 alien species (from families Apocynaceae, Asteraceae, Brassicaceae, Fabaceae, Lamiaceae, Polygonaceae, Solanaceae) in Novosibirsk Region. For Vincetoxicum hirundinaria Medik. (2n = 22) and Sisymbrium altissimum L. 14), were determined first time on material from Russia; Betonica officinalis 16) – Asian Stachys annua (L.) 34) West Siberia. C...

Initial morphometric data and descriptions of males and the four juvenile stages of Xiphinema coxi coxi Tarjan, 1964 collected from soil about the roots of alfalfa (Medicago sativa L.) at Gainesville, Florida, and from a greenhouse microplot at Fayetteville, Arkansas, are given. Males were similar morphometrically and in shape to females and had 3-5 preanal supplements. The four juvenile stages...

The xylem of alfalfa (Medicago sativa L.) was found to be susceptible to vascular obstruction by picomole quantities of dextrans. Not all parts of the xylem were equally susceptible to this plugging. The quantity of dextran of 2 x 10(6) molecular weight required to stop vascular flow was 8 picomoles in petiole junctions and 0.4 picomole in leaflet veins. Vascular flow through stems was greatly ...