Sultana vines in the field grafted on any one of a number of rootstocks being tested for compatibility showed substantially reduced petiole chloride as compared with ungrafted sultanas. Self grafted sultanas did not differ from ungrafted in chloride status. There were significant differences between the various effective rootstocks - the degree of reduction of chloride concentration was better than 50 per cent for Dogridge and 1613 stocks, but about 75 per cent for Salt Creek and 101-14.

Five species of Discolaimus collected from Australian mallee soils are described: D. major, D. texanus and three new species. In each species the lip region is an expanded, saucer shaped disc with distinct rim, divided by grooves into six sectors on the anterior surface, and variously lobed on the under surface. D. agricolus n. sp., monosexual, L = 1.30-1.73 mm, V = 45-48, odontostyle = 21-23 μm, has a multi-lobed lip region similar to D. major and an anterior oesophagus of uniform diameter throughout. D. silvicolus n. sp., monosexual, L = 1.16-1.89 mm, V = 51-53, odontostyle 20-22 μm, has a distinctively lobed lip region and prominent sheath around the basal oesophageal expansion. D. elegans n. sp., monosexual, L = 1.11 to 1. 20 mm, V = 50-53, odontostyle 14-15 μm, has three rows of lateral body pores. In D. major, D. agricolus and D. silvicolus a group of large cells of unknown function is present in the cardiac region. Two subventral longitudinal grooves in the odontostyle and numerous ventral and dorsal body pores are present in all five species.

Head structures are described and compared from scanning electron micrographs for 13 species of Acrobeles, Stegelleta, Zeldia, Chiloplacus, Nothacrobeles, Pseudacrobeles and Acrobeloides. The lip region in Acrobelinae is conical, sometimes significantly elongate quite apart from the impression of elongation conferred by the development of lip appendages-labial and cephalic probolae-characteristic of the subfamily. The level of insertion of the labial probolae on the oral cone structure is close to the top of the cephalic probolae. Although cephalic probolae are flap like; the major part of each probola is directly attached to the oral cone, usually through a radial ridge connecting it to tangential ridges joining the bases of the labial probolae. The disposition of lip region scnsilla suggests that the three labial probolae and the six, or three, cephalic probolae are each outgrowths of the lip sectors. Where appendages are three in number, each is formed by fusion from two adjacent sectors. In some genera/species the lips are represented by distal lobes, not modified to cephalic probolae.

G. graciloides is redescribed from Karelia, USSR. It has an almost smooth cuticle, obscure lateral field and deirid, no phasmids, distinct labial disc, amphidial apertures on anterior surface beyond the labial disc, spermatheca offset, crustaformeria as quadricolumella. Males are described for the first time. The relationships of Gracilancea Siddiqi, 1976 are discussed.

Ten species of Tylenchidae and three species of Boleodoridae were examined in SEM and divided into three groups. The first one consists of Tylenchus davainei, Filenchus thornei, Irantylenchus vicinus, Tylenchus ditissimus and Lelenchus leptosoma. These are characterised by small pits near oral opening, no offset disc, four incisures in the lateral field (except L. leptosoma), wide vulva, and presence of hypoptygmata. Ottolenchus facultativus is similar to these species. The second group includes Aglenchus agricola, Coslenchus costatus and C. alacinatus. The oral opening in these is also surrounded by small pits which, together with amphidial apertures, are located on an offset disc; lateral field formed by distinct ridges, vulva small and located in a vulval cavity, hypoptygmata present. Cephalenchus emarginatus is close to this group. The third group includes Basiria gracilis, Neopsilenchus magnidens and Boleodorus thylactus. In these the oral opening is surrounded by six larger papillae, a second circle of cephalic sensory organs is formed by four sublateral papillae, amphids laterally on the head to form an open V, lateral field and vulva as in the first group. The diagnosis of Boleodoridae is emended, as well as those of Boleodorinae (syn. Basiriinae) and Psilenchinae (syn. Antarctenchinae). Classification of Boleodoridae is outlined and a key to the genera provided.

Tylenchorhynchus tobari n. sp., monosexual, L = 0.61-0.77 mm, V = 51-56, stylet = 17-19 μm, is distinguished by its four-lobed lip region with thin four-lobed disc, narrow body annules with longitudinal striae on neck, cuticular markings in mid ventral line behind vulva, about 50 annules on tail, non-annulated terminus. Tylenchorhynchus velatus n. sp., bisexual, L = 0.66-0.80 mm, V = 51-57, stylet = 22-25 μm, is distinguished by its six-lobed lip region with thin oval disc, vulval sheath about 10 μm long, tail with about 25 annules, annulated terminus. Morulaimus simplex n. sp., bisexual, L = 1.15-1.61 mm, V = 51-59, stylet = 62-74 μm, is distinguished by its continuous lip region less elaborately divided than in other known species, inconspicuous labial framework, prominent sclerotisation behind basal plate, tail with 35-45 annules, terminus annulated.

A study of specimens of Thornenema cavalcantii, T. mauritianum, T. baldum, T. caudatum, T. longicaudatum and T. qaiseri n. sp. from Australia or Malaysia suggested that T. caudatum, T. longicaudatum, T. wickeni and probably T. loofi, form a group distinct from other species. Differences included narrowed lip region, narrow amphids, spathulate sclerotisation of the labial framework, and unusual spear shape. T. qaiseri n. sp. is described. Specimens of T. cavalcantii included three didelphic females.

The subfamily Belonolaiminae was redefined by Siddiqi (1970) and Golden (1971), both independently establishing Belonolaimidae. Both included Belonolaimus Steiner and Morulaimus Sauer in the subfamily, but Carphodorus Colbran, included by Golden, was assigned to the Telotylenchinae by Siddiqi. Andrassy (1976) synonymised Carphodorus with Belonolaimus, without giving reasons. Monteiro and Lordello (1977) added a new genus, Ibipora, which they differentiated from Belonolaimus by the number of lateral lines, transferring B. lineatus Roman to Ibipora. No detailed description of the lip region of Carphodorus has been published. The structure of the feeding apparatus in this group is obscure. Apart from the observations of Seinhorst (1971 a), there is little information about the disposition of the oesophageal glands. We have undertaken a comparative morphological study of some of the features of the subfamily.

Loveys (pers. comm.) showed that xylem sap from tomato plants grown under fluorescent light contained more cytokinin than from plants illuminated by tungsten filament lamps. In his experiments there was no difference in either the temperature or the amount of photosynthetically active radiation (400-700 nm). At present there is some conflict expressed in the literature about the influence of cytokinins on nematode growth in susceptible plants. On the one hand Brueske and Bergeson (1972) have shown that root-knot nematodes can cause a decrease in the amount of cytokinin in the root tissues and xylem exudates of tomatoes, and on the other, van Staden and Dimalla (1977) have shown that root-knot nematodes increase the amounts of cytokinins in roots, but do not appear to alter the cytokinin complement of the xylem sap. They thought the change to cytokinin concentrations in infected roots was due to accumulation of cytokinins by the nematodes themselves (Dimalla and van Staden, 1977). There appears to be a relationship between the degree of resistance to nematodes in plants and the presence of cytokinins. Thus Dropkin et al. (1969) and Kochba and Samish (1971) have shown that exogenously supplied cytokinins make resistant tomato plants more susceptible, and Kochba and Samish (1972) have shown that cytokinin levels are lower in resistant peach rootstocks than in susceptible ones. However, Skene and Antcliff (1972) did not find any difference in the cytokinin content of the sap from the nematode-resistant rootstock Salt Creek compared with the susceptible Sultana rootstock. In the investigation described here we observed the growth of Meloidogyne javanica (Treub) Chitw. in plants grown under conditions known to lead to changes in the cytokinin levels of the sap.

Acrobeles complexus, A. chelatus, Zeldia punctata, Nothacrobeles subtilis and N. maximais were studied with the scanning electron microscope with particular attention to morphology of the cephalic region. Each genus had a broad anterior chamber in the stoma. Number and arrangement of cephalic sensory organs was the same for all species. Males, seen in two species of Acrobeles and N. maximus, had two grooves and ventral papillae associated with the cloaca.

Four species of Discocricronemella were found in virgin jungle in the Pasoh Forest, Negeri Sembilan, Malaysia. These were D. limitanea (Luc), D. macramphidia De Grisse, and two new species described as D. retroversa n. sp. and D. pannosa n. sp. Females of D. retroversa have a stylet 88-97 μm long, 94-105 body annules and the submedian pseudolips have hyaline surrounds; females of D. pannosa have a stylet 96-113 μm long, 65-72 body annules. Males of all four species were found.

Uncer t a in t i e s a b o u t the iden t i ty of Xiphinema ensiculiferum (Cobb, 1893) Thorne, 1937 (2, 11) have been resolved in a redescription by Southey and Luc (10) based on a topotype population. X. ensiculiferum of Loos (6) and X. ensiculiferum of Luc (7) were assigned to new species, X. loosi and X. h y g r o p h i l u m , r e s p e c t i v e l y ; a n d X. ensiculiferoides Cohn and Sher (3) was synonomized with X. ensiculiferum. The status of X. ensiculiferum of Carvalho (1) remains uncertain. Yeates (12) also described X. ensiculiferurn (under the name ensiculiferoides) from specimens collected in the New Hebrides. His description included details of the four larval stages. No males of X. ensiculiferum sensu stricto have been reported. We found X. ensiculiferum in three soil samples from about the roots of tea (Thea sinensis L.) and wild banana (Musa sp.) in West Malaysia. Material available for study included 24 females, 23 juveniles, and one male. Specimens were killed and fixed in hot F.A. (4:1, v/v) (9), processed to glycerine by the rapid method of Seinhorst (8), and mounted in anhydrous glycerine. The solitary male (Fig. I-A,B) had the following dimensions: L = 1.64 mm; a = 27; b = 3.9; c = 66; fixed ring of spear guide 130 #m from anterior end; odontostyle 140 #m; spear extension 74 #m; spicules (on arc) 65 #m; lateral guiding piece 20 #m; Body only slightly arcuate, apart from strong curvature of the caudal region. Rounded lip region slightly set off from body. Amphids only partly visible because specimen not perfectly lateral. Lateral chord nearly one-quarter of body width. Details of testes were completely obscured by dense body contents. An adanal pair and three ventromedian supplements were present, the latter spaced rather more

Species of Helicotylenchus are common in the soils of West Malaysia, both cultivated and uncultivated. The most widely distributed species are H. dihystera (Cobb) and H. multicinctus (Cobb). H. pseudorobustus (Steiner), H. abunaamai Siddiqi, and H. crenacauda Sher, have also been identified from cultivated soils. H. erythrinae (Zimmermann) and two new species H. pasohi and H. paracanalis, have been found in uncultivated jungle soil. H. pasohi is a bisexual species close to H. exallus Sher, with more posteriorly placed vulva, indented tail, and phasmids at anal level. H. paracanalis is close to H. canalis Sher with prominent lateral canals, but is bisexual.