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HAUSTORIUM Parasitic Newsletter Official Organ of the International Parasitic Seed Research Group

February 1995 ...... Number 30

grains were grown (3-6 days) into seedlings which SIXTH INTERNATIONAL PARASITIC presumably release the strigol related substance sor- WEED SYMPOSIUM golactone on the filter paper. In the control experi- CORDOBA, SPAIN 16-18 APRIL 1996 ments, preconditioned (10-12 days at 25 O C) herrnonthica seeds on glass fiber filter paper were Plan to attend the symposium in beautfiul Cordo- placed in the petri dish with the seedlings, ba, Spain where in addition to plenary sessions, incubated at room temperature and the germinated papers, and posters there will be opportunity to see seeds counted. The soil microorganisms to be tested Orobanche, Cuscuta. and Viscum in the field. Like for their ability to nullify the effect of the stimulant previous symposia, all groups of parasitic plants are are grown on nutrient agar plates, the cell population included. For information contact: suspended in distilled water and the suspension used Secretaria de "6th Parasitic Weed Symposium" in the test experiment. Here the bacterial suspension Centro de Investigacion y Desarrollo dgrario (inhibitor carrier) was added together with the Striga hpartado 4240 seeds to the petri dish carrying the sorghum seedlings. 14080 Cordoba The isolate most commonly used was a mucoid, yel- SPAIN lowish bacterium (probably a Xanthomonas sp.), orig- Fax: (country code 34) 57 202721 inally isolated as a sorghum seed pathogen and was routinely propagated on sorghum seedlings in petri dishes. The addition of the bacterial suspension to the 0 BACTERIA THAT SCAVENGE stimulant source reduced the ability to germinate the GERMINATION STIMULANTS? Striga seeds. About 65% of the Striga seeds germinat- ed in the absence of the bacterial suspension (control) There is a microbiological principle stating no while only 8.4% germinated in the presence of the naturally occurring substance exists that cannot be microorganisms (Treated.) In a supportive experi- broken down by a microorganism. Striga depends on ment, sorghum grains were grown in sterile sand in the production of tiny seeds that are stimulated to plastic cups for one week and watered with test bac- germinate by chemical stimulants of which strigol is terial suspension or with distilled water. Then the the best known. Strategy in the present research is to water was removed by a vacuum pump and used to find a way to intervene into this process by interfer- stimulate Striga seeds. Controls gave 55.5% germina- ing between the stimulant, whether strigol or one of tion while test experiments gave 27.4% germination. its closely related analogs, and Striga seed. This A few pot experiments were also carried out in which project aims at finding a soil microorganism that sorghum seedlings were transferred from the petri could scavenge strigol as it exudes from the host root dishes to large clay pots containing garden soil infest- before it reaches the striga seed. Probability that such ed with Striga seeds at the rate of 0.08 grams per an organism can be found should be high because the pot. The sorghum was grown for 44 days and plants microorganisms could have a number of other func- watered with bacterial suspensions or with distilled tions not confined to breaking down the probably- water. Then. the plants were uprooted and the recalcitrant heterocyclic strigol molecule. Simple tech- attachments of the Striga to the sorghum roots were niques have been followed to test the hypothesis. counted. The results obtained showed that when bac- Most of the work was carried out in sterile petri dish- terial suspensions were added to the soil the attach- es with moistened filter papers on which sorghum PUBLISHED BY OLD DOMINION URIVERSITY 1 c

meiitz of >tripto hnzt roots axeraged 36; in the con- mozt dioecious lfrican occur in 5ome species. Female nature of the inhibitor. In one experiment, we sepa- biased sex ratios were found over all populations of rated the liquid from the cell mas3 in the suspension, Phoradendron tomentosum in Central Texas bj Nixon nsing a 0.45 micron bacterial filter. and tested the and Todzia. Recently Marshall et al. stated that, abilitj of each to inhibit the germination stimulant. unique among the studied to date, the sex The effectix e ingredient resided in the filtrate not in ratio of Phoradendron juniperinum populations is sig- the cell mass. Heat treatment destroyed the ability of nificantly male biased. In populations of Loranthus the inhibitor to ha\e any effect on the stimulant sug- europaeus, parasitizing oaks (Quercus cerris and Q. gesting that the inhibitor is a volatile substance or a petraea), I found male bias. Male plants prevailed: protein that is denatured by heat. From a biotechno- they formed 69.2% of all living plants. This male logical vie\$ point. once a suitable organism has been biased sex ratio was in relation to the woodland coe- obtained and the mechanism of its action on the stim- nopopulation of Loranthus. Biological and ecological ulant has been elucidated, the useful ingredient can causes of the variations in sex ratios in mistletoes are be obtained by growing the organism in a suitable not known. Barlow found that in dioecious species of growth medium in bioreactors. If the cells themselves Viscum, males are normally heterozygous for sex asso- are to be mixed with the seeds of sorghum before ciated chromosomal translocations, and in V. album sowing as a dressing, then they can be provided in male plants usually form a ring of eight to ten chro- dry powder form like any other commercial microbial mosomes at meiosis. Nixon and Todzia found that only preparation. Obviously microbes that are pathogenic the trees with one exhibited a sex ratio near (e.g., the strain used here) cannot be used. If a 1:1. Trees with two or more mistletoes generally chemical produced by the organism is the effective showed female biased ratios. The authors suggested ingredient, then it could be produced in pure form. that a general trend of increased within tree female Both preparations should pose no environmental bias is associated with higher number of mistletoe per problems. The technology needed for the production tree. But Loranthus europeaus showed similar 5ex rat- of large scale biomass or chemical is available today. ios in both the woodland and within host tree popula- The yields can be improved through modern tech- tions. We need more information about sex ratios in niques of process optimization, and the microbial several mistletoes species and in several environmen- strains could be improved using recombinant DNA tal conditions. In mistletoe population dynamic studies technology. It may even be possible to transfer the it is important to accept the dioecy and sex ratio bias. genes concerned from the microorganism to the host plant itself to make it intrinsically resistant to Striga. Pavol Elias, Institute of Botany, Slovak Acad- We believe that this research could open an area of emy of Sciences, Dubravslca 14, SK-842 23 Bratisla- useful research in weed control as the technique va, Slovakia could equally well be applied to the control of similar parasitic weeds.

Hamid Ahmed Dirar, Faculty of Agriculture, Omar 0 PROCEEDINGS OF THIRD Mukhtar University, A1 Beida, Libya OROBANCHE SYMPOSIUM

The proceedings can be obtained from: KIT 0 SEX RATIO IN MISTLETOES Press, Royal Tropical Institute, Mauritslcade 63, 1092 AD Amsterdam, NETHERLANDS. The cost is There are many dioecious mistletoes from the 55 US$ + $12 for mailing surface mail and $24 for new and the old world. The sex ratio of many dioe- air. Payment is to be made upon receipt of the vol- cious plants often deviates significantly from 1:l with ume. When ordering, indicate mode of shipment. (See tendency towards a male bias. Earlier sex ratio sur- literature section below under Pieterse etc for com- veys on mistletoes have reported a female-bias. Vis- plete citation. See HAUSTORIUM 29 for a report on cum album populations have a strongly female biased the symposium.) sex ratio in natural populations, but in other Europe- an and Asian species of Viscum sex ratios not differing from 1: 1 have been found. Sex ratios were at unity in 0 LITERATURE

Page 2 *. Haustorimii 30

4b bashes -\M ad lhhashrr. 1995. ~Iicrrrorgaiiistri~ seeds. P~T5iologia Plantarum 91: 529-534. (con- associated i\ith Striga hermonthica and possil&- firming a 5bnergistic interaction betu emthidia - tic5 of their utilization as hiological control zuron and auxins.) agents. PLITS 12 (1): 144 p. (28 fungal species Banerjre, K., D. C. Khatua and N. Mukherjee. 1993. recorded in Sudan of which Fusarium nygamai Some new hosts of Cuscuta sp. Indian Forester and F. semitectum \ar. majus shosc potential for 119: 760-761. (Recording occurrence on a range development as mycoherbicides.) of forest tree species, leading to death of Milling- Abu-Irmaileh, B. E. 1994. Nitrogen reduces branched tonia hortensis.) broomrape (Orobanche ramosa) seed germina- Berner, D. K., A. E. Awad and E. I. Aigbolchan. tion. Weed Science 42: 57-60. (Laboratory study 1994. Potential of imazayuin seed treatment for showing that N 20-100 mg/l, as ammonium control of Striga gesnerioides and Alectra rogelii nitrate, reduced germination of 0. ramosa when in cowpea (Vigna unguiculata.) Plant Disease host seedlings and parasite seed were continuous- 78: 18-23. (Soaking cowpea seeds in imazayuin, ly exposed for 30-35 days.) e.g. 3.6 mgil for 5 minutes before sowing, almost dlabi, M. O., D. K. Berner and G. 0. Olanyan. 1994. prel ents parasite development.) Characterization of soybean cultivars for Striga Butler, L. G. 1995. Chemical communication between hermonthica control. Abstract 67 1. Phytopathol- the parasitic weed Striga and its crop host. A ogy 84: 1151. new dimension in allelochemistry. pp. 158-168 Andrews, D. J. and P. J. Bramel-Cox. 1993. Breeding in Dakshini, K. M. M. and F. A. Einhellig, rdi- cultivars for sustainable crop production in low- tors. Allelopathy. Organisms, Processes, and input dryland agriculture in the tropics. pp L4pplications.Washington: American Chemical 211-223 in: Buxton, D. R. et al. (Eds) Interna- Society. ACS Symposium Series 582. (A helpful tional Crop Science 1. International Crop Sci- summary of chemical signals in the Striga life ence Congress, Ames, 1992. Crop Science Socie- cycle. j ty of America. (Including consideration of Canevari, M. and E. Sieckert. 1993. Timing and rate sorghum resistance and yield loss due to Striga of MON 13200 for dodder control in alfalfa. In: SPP *I Lvm, R. G. (Ed.) Proceedings, Western Society Andary, C., R. Wylde, L. Maury, A. Heitz, A. of Weed Science 46: 20-21. (Thiazopyr at 1 lb/ Dubourg, and S. Nishibe. 1994. X-ray analysis ac applied to established alfalfa in January pro- and extended NMR study of oraposide. Phyto- vided good control of Cuscuta through to chemistry 37(3): 855-857. August.) Ariga, E. S., D. K. Berner and J. Chegwa. 1994. Carsky, R. J., L. Singh and R. Ndikawa. 1994. Sup- Effects of previous season cotton and cowpea on pression of Striga hermonthica on sorghum using Striga hermonthica parasitism on . Abstract a cowpea intercrop. Experimental Agriculture 670. Phytopathology 84: 1151. 30: 349-358. (More evidence for the possible Aronne, G., C. C. Wilcox and P. Pizzolongo. 1993. value of cowpea interplanted within the row in Pollination biology and sexual differentiation of reducing Striga density and seed production.) alba () in the Mediterranean Carsky, R. J., L. Singh and R. Ndikawa. 1994. Effect region. Plant Systematics and Evolution 188 (2): of herbicide and handweeding on current and 1-16. subsequent season Striga hermonthica density on Assefa Admasu and Endale Berhe. 1994. Orobanche sorghum. International Journal of Pest Manage- crenata a potential threat to food legumes in ment 40: 111-116. (No significant effect from 2 Ethiopia. EWSS Newsletter (Ethiopian Weeds seasons of suppression, but initial infestation Science Society) 2(1): 1-2. (The first record of very high - > 100/m2.) this species in Ethiopia, at two sites near Dessie Carter, R. J. and D. A. Cooke. 1994. Broomrape - a threat to the important faba bean crop.) (Orobanche spp.) is a threat to broadleaved Atkinson, K., editor. 1994. IITA Annual Report crops in . Plant Protection Quarterly 9: 1993. International Institute of Tropical Agricul- 61-63. (Including a useful key for separation of ture. (Includes section on Striga research accom- the main weedy species, not yet established in plishments .) Australia, from the native Orobanche cernua var. Babiker, A. G. T., T. Cai, G. Ejeta, L. G. Butler and australiana.) pi'. R. W-oodson. 1994. Enhancement of ethylene Cechin, I. and M. C. Press. 1994. Influence of nitro- biosynthesis and germination with thidiazuron gen on growth and photosynthesis of a Cg plant, and some selected auxins in Striga asiatica Oryza sativa infected with the root hemiparasite,

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Stnga hermonthzca. Journal of Experimental to biotic and abiotic stresses. Euphrtica 73: Botany 45: 925-930. (PhotosTnthesis reduced bv 127 - 135. (Noting the lack of sources of resis- 30 arid 44% at high and lo^ Iv rebpectiteh ,) tance to Orobanche spp. in lentil.) Cechin, I. and BI. C. Presi. 1994. The influence of Fer, A,, J. C. Painset and L. Rey. 1992. nitrogen on growth and photosynthesis of sorg- [Characteristics of mineral nutrition in some hum infected with Striga hermonthica from dif- types of parasitic plants (Cuscuta, Orobanche. ferent provenances. Weed Research 34: Thesium) and their development on crops.] Bul- 289-298. letin de la Societe Botaniyue de France, Actual- Chowdhury, Al-Mamum and A. Ahmed. 1993. Histo- ites Botaniques 139: 111-121. (Observations on pathological studies of Striga spp. with K levels in host and parasite suggest that Cuscu- roots. Journal of Mycopathological Research ta and Orobanche obtain nutrients mainly from 31(1): 1-4. (Observations on S. asiatica and S. the host phloem, while Thesium obtains them densiflora.) from host xylem.) Condon, J. and J. Kuijt. 1994. Anatomy and ultras- Fer, A., N. Russo, P. Simier, M-C. -4rnaud and P. tructure of the primary endophyte of Zleostylus Thalouarn. 1994. Physiological changes in a root mzcranthus (Loranthacear .) International Journal hemiparasitic angiosperm, Thesium humile (Sam of Plant Science 155(3): 350-364. talaceae) before and after attack. Journal of Cubero, J. I., S. Khalil, and M. T. Moreno. 1993. Plant Physiology 143: 704-710. (Growth and Problems and prospects of selecting for Oro- photosynthetic rate in unattached parasite banche resistance in cool-season legumes. pp. declines after 2 weeks, perhaps associated with 167-177 in Singh, K. B. and Saxena, M. C. (Eds) high N/low P uptake by parasite roots. Initial Breeding for Stress Tolerance in Cool-season photosynthesis comparable with that of wheat.) Food Legumes. John Wiley. Fernandez-Rivera. S. and D. E. Hess. 1994. Chemical Dawoud, D. A. and J. Sauerborn. 1994. Impact of composition of Striga herbage and its intake and drought stress and temperature on the parasitic digestion by sheep. Abstract 675. Phytopthology weeds Striga hermonthica and Alectra vogelii in 84: 1151. their early growth stages. Experimental Agricul- Filip, G. M., J. J. Colbert, C. G. Shaw, P. Hessburg ture 30: 249-257. and K. P. Hosman. 1993. Influence of dwarf Dawson, J., Musselman, L. J., Doerr, I. and P. Wol- mistletoe and western spruce budworm on swinkel. 1994. Biology and Control of Cuscuta. growth and mortality of Douglas-fir in unman- Reviews of Weed Science 6: 265-317. (A com- aged stands. Forest Science 39: 465-477. prehensive survey of virtually every aspect of (Results showed serious effects from both pests dodders: ecology, floral biology, . dis- but no synergistic interaction between them.) tribution, ethnobotany, physiology, haustorial Frischmuth, K., A. Marx, T. Petrowitsch, U. Wagner, structure, control and more with extensive bibli- K. Koerner, S. Zimmerman, H. Meuer, W. S. ography and numerous illustrations.) Sheldrick, and P. Welzel. 1994. Strigol synthetic Dembele, B., A. Raynal-Roques, G. Salle, and C. studies: The first synthetic approach that allows Tuquet. 1994. Plantes Parasites des Cultures et control of C-2’ configuration. Tetrahedron Let- des Essences Forestiees au Sahel. CTAIJohn Lib- ters 35(28): 4973-4976. bey Eurotext. 43 pp. (A beautifully illustrated Garcia-Torres, L., F. Lopez-Granados and M. account of a wide range of parasitic species in Caste jon-Munoz. 1994. Pre-emergence herbi- West .) cides for the control of broomrape (Orobanche Dieringer, G. and C. R. Werth. 1994. Population cernua Loefl.) in sunflower (Helianthus annuus genetic structure of Agalinis strictifolia (Scro- L.) Weed Research 34: 387-402. (Reporting phulariaceae.) Bulletin of the Torrey Botanical highly selective control from imazethapyr, imaza- Club 121(2): 148-153. pyr and chlorsulfuron.) Erslcine, W. and M. C. Saxena. 1993. Problems and Gomes, 4. L. and G. W. Fernandes. 1994. Influence prospects of stress resistance breeding in lentil. of parasitism by Pilostyles ingae (Rafflesiaceae) In: Singh, K. B. and Saxena, M. C. (Eds) Breed- on its host plant Mimosa naguirei (Leguminosae.) ing for Stress Tolerance in Cool-season Food Annals of Botany 74: 205-208. Legumes. John Wiley. pp. 51-62. Grimble, D. G. and R. C. Beckwith 1993. Temporal Erslcine. W., M. Tufail, A. Russel, M. C. Tyagi, M. M. changes in presence of late instar Mitoura spine- Rahman and M. C. Saxena. 1994. Current and torum (Lyceanidae) in eastern Oregon. Journal future strategies in breeding lentil for resistance of the Lepidopterists’ Society 47: 329-330. (On

Page 4 Hauz to rium 3 0

dr-ccuthobium camplj lopodurn on Pinus ponder-o- Netibletter 33: 30-32. (Do5e- of 75 g aiiha pre- su.) or 20 g ai:ha po

Page 5 Lahrada. R.. J. C. Ca>ele\ and C. Parker. 1994. Panda. 31. 31. and N. I<. Cho~idh~i~.1993. Effects of R erd Management for Det eloping Countries. nutrients on chlorophb 11 content and photochem- FIO Plant Production and Protection Paper ical activities by isolated chloroplaiti of Cuscuta 120. FAO, Rome. 384 pp. (Includes sections on reflexa. Plant Physiology and Biochemistn (New Cuscuta bl Li. Str-iga by Musselman and Oro- Delhi) 19: 6-10. banche by Sauerborn. Available on request from Pate. J. S.. G. Woodall, W.D. Jeschlce and G. R. the senior author, Plant Protection Service, Stewart. 1994. Root xylem transport of amino FAO, Rome 00100, Italy.) acids in the root heiniparasitic shrub Olax phyl- Leake, J. R. 1994. Tansley Review No 69. The biolo- Zanthi (Labill.) R. Br. (Olacaceae) and its multi- gy of myco-heterotrophic (’saprophytic’) plants. ple hosts. Plant, Cell and Environment 17: New Phytologist 127: 171-216. (A comprehen- 1263-1273. [Amino acids in the parasite occa- sive review relating to 400 species in 87 genera, sionally reflect those of the host but ’pronounced discussing among much else whether ’saprophy- metabolic transformations’ are demonstrated. tic’ plants are symbiotic with, or parasitic upon, Some observations also on Exocarpus spartens their associated fungi.) (Santalaceae) which was parasitized by, but did McKinnel, F. H. (ed.) 1993. Sandalwood in the Pacif- not parasitize, Olux.] ic Region. Australian Council for International Pazy, B. and U. Plitmann. 1994. Holocentric chromo- Agricultural Research. 43 pp. (Surveying biodi- some behap iour in Cuscuta (Cuscutaceae.) Plant versity, cultural practices and uses for timber, Systematics and Evolution 191: 105-109. aromatic oil and fruit.) Pieterse, A. H., J. A. C. Verkleij and S. J. ter Borg Marshall, J. D., J. R. Ehleringer, E. D. Schulze and (Eds.) 1994. Biology and Management of Oro- G. Farquhar. 1994. Carbon isotope composition, banche. Proceedings of the Third International gas exchange and hypertrophy in Australian mist- Workshop on Orobanche and related Striga letoes. Functional Ecology 8: 237-241. Research. Royal Tj qJpical Institute, The Nether- Mauseth, J. D. 1993. Cacti, mistletoes and desert sur- lands. 736 pp. (Containing 96 papers, which will vival. Cactus and Succulent Journal 65: not be separately listed in Haustorium - see sep- 172-175. (Concerning aphyllus on cacti arate announcement for further information.) in Chile.) Porta-Puglia, A., K. B. Singh and A. Infantino. 1993. Mbuga, A. M. and A. T. Obilana. 1993. Distribution Strategies for multiple-stress resistance breeding and host specificity of Striga asiatica and S. her- in cool-season food legumes. pp. 411-427 in K. monthica on cereals in - a preliminary B. and Saxena, M. C. (Eds) Breeding for Stress study. International Journal of Pest Management Tolerance in Cool-season Food Legumes. John 39: 449-451. Wiley. Moors, A,, D. I<. Berner and P. Van Damme. 1994. Prance, G. T. and P.H. Raven, editors. 1995. The Identification of nonhosts for control of Striga World of Plants. Weekly Encyclopedia 40(1/22): gesnerioides. Abstract 672. Phytopthology 84: 97-128. Tokyo: Asahi Shimbun Publishers. (Pop- 1151. ular treatment with spectacular photographs of Nair, A. G. R. and G. Thirupurasundari. 1992. Cou- the most bizarre of all angiosperm families: the marins and flavonoids from Cuscuta reflexa par- Rafflesiaceae, Mistrastemonaceae, Hydnoraceae, asitic on Bouganvillea spectabilis. Fitoterapia Balanophoraceae, Eremolepidaceae, Viscaceae, 63: 381-382. Loranthaceae, Misodendraceae, Santalaceae, Opi- Ndirpaya, Y. D., D. K. Berner and L. J. Musselman. liaceae, Olacaceae, Diptentodontaceae, and 1994. Germination requirements of Striga asp- Medusandraceae by leading students of each fam- era. Abstract 673. Phytopathology 84: 1151. ily. In Japanese but with Latin names on photo- Nickrent, D. L., K. P. Schuette and E. M. Starr. graphs.) 1994. A molecular phylogeny of Arceuthobiurn Prather, L. A. and R. J. Tyrl. 1993. The biology of (Viscaceae) based on nuclear ribosomal DNA Cuscuta attenuata Waterfall. Proceedings of the internal transcribed spacer sequences. American Oklahoma Academy of Science 73: 7-13. (Unlike Journal of Botany 81: 1149-1160. most species of dodder, C. attenuata has a Overton, J. M. 1994. Dispersal and infection in mist- restricted host range, preferring Iva annua; letoe inetapopulations. Journal of Ecology 82 : Asteraceae.) 7 11-723, (PhrygZanthus sonorue (Loranthaceae) Press, M. C., A. N. Parsons, A. W. Maclcay, C. A. Vin- in Baja California shows little or no host prefer- cent, V. Cochrane and W. E. Seel. 1993. Gas ence.)

Page 6 evcliange characteristics and nitrogen relations of 9: 77-80. (Referring to the use of synthetic stri- ti$o Mediterranean root hemiparasites: Bartsza go1 analogs.) tr-ixcigo and Parentucellia tiscosa. Oecologia 95 : Shan. C. G. and D. Phanichapol. 1993. First report 155-15 1. of Dendrophthoe falcata on Pinus kesiya. Plant Press, 31. C. and J. B. 'Khittalcer. 1993. Exploitation Disease 77: 847. of the xylem stream by parasitic organisms. Phil- Shaxon, L. J.. C. R. Riches and J. H. Seyani. 1993. osophical Transactions of the Royal Society of Incorporating farmer knowledge in the design of London. Series B, Biological Sciences 341: weed control strategies for smallholders. Pro- 10 1- 111. (Relating especially to Striga asiatica ceedings, Brighton Crop Protection Conference, and Viscum album.) Weeds. 1993. Vol. 3. pp. 1149-1154. (With par- Ramlan, M. F. 1994. Environment and the host- ticular reference to Striga spp. in Malawi.) parasite interactions between Striga hermonthica Singh, A. and Singh, M. 1993. Cell wall degrading and sorghum. PhD Thesis. York University, UK. enzymes in Orobanche aegyptiaca and its host 161 pp. Brassica campestris. Physiologia Plantarum 89: Rao, P. N. and K. I<. Neelai. 1993. Diversity in the 177-181. (Suggesting cellulase and polygalactura- host range of China dodder. pp. 1-6 in K. Udai- nase to he the main enzymes involved in hausto- van. I<. Janardhanan, S. Manian and V. R. IC. rial penetration.) Reddy (Eds) Proceedings of the National Seminar Smith, L. C. 1993. Studies on Zea mays infected with on biodiversity : strategies for conservation and Striga hermonthica, with particular reference to future challenges. Coimbatore, 1993. (Listing a photosynthesis. PhD Thesis, Uniiersity of Lon- wide range of hosts of Cuscuta chinensis in don. 170 pp. (Striga infection resulted in reduc- India, including the crops pigeon pea, sunn tion in photosynthesis, perhaps via changes in hemp. Phaseolus trilobus and Vigna mungo.) hormone levels and resultant changes in cell wall Sharma, S. B., D. H. Smith, P. Subrahmanyam, M. J. structure.) Freire, T. Faria, D. R. Butler and G. V. Ranga Smith, R. B., E. F. Wass and M. D. Meagher. 1993. Rao. 1994. Parasitism of groundnut by Striga sp. Evidence of resistance to hemlock dwarf mistle- in Mozambique. International Arachis Newsletter toe (Arceuthobium tsugense) in western hemlock 14: 24-25. (Confirming the parasitism of groun- (Tsuga heterophylla) clones. European Journal dut by an identified Striga sp., likely S. gesner- of Forest Pathology 23: 163-170. ioides.) Sontakey, P. Y., W. M. Dabre, R. D. Deotale, V. K. Riches, C. R. 1994. Variability of parasitic weeds and Mohod and D. R. Kene. 1992. Correlation their hosts: implications for witchweed manage- among morpho-physiological and biochemical ment in Africa. In: The Impact of Genetic Varia- constituents in Striga resistant and susceptible tion on Sustainable Agriculture. Aspects of cultivars of sorghum. Journal of Soils and Crops Applied Biology 39. Association of Applied Biol- 2( 1): 32-34. (Showing positive correlation ogy. pp. 145-154. between Striga-resistance and hydrocyanic acid Riches, C. R., L. J. Shaxson, J. W. M. Logan and D. levels in leaves at 30 days.) C. Munthali. 1993. Insect and parasitic weed Soria, S., D. Cadahia and A. Munoz. 1993. (The genus problems in southern Malawi and the use of Carulaspis Mac. Gillivray, 192 1 (Hornoptera, farmer knowledge in the design of control meas- Diaspididae) in the gardens of Patrimonio ures. Network Paper - Agricultural Administra- Nacional.) Boletin de Sanidad Vegetal, Plagas 19: tion (Research and Extension) Network 42: 1-17. 273-284. (Occurs on Viscum album in Spain.) ODA, London. Srivastava, S., A. Nighojkar and A. Kumar. 1994. Runge-Metzger, A. 1993. The economics of Striga Multiple forms of pectin methylesterase from control in different farming systems in northern Cuscuta reflexa filaments. Phytochemistry 37: Ghana. Report PN 87.3540.9-01.200, Supra- 1233-1236. regional Project, Ecology and Management of Suzuki, Y., Yun-Hui Zhang, N. Murofushi and Y. Talc- Parasitic Weeds. GTZ-UH. 51 pp. (A thoughtful euchi. 1994. Endogenous gibberellins in clover analysis of various socio-economic factors, broomrape, a and its host, clover: emphasizing the need for more long-term studies dependency of the parasite on the host for gib- and data.) berellin production. Journal of Plant Growth Saghir, A. R. 1994. An overview of a new technique Regulation 13: 63-67. (The range of gibberellins in Orobanche control. Plant Protection Quarterly in 0.minor is similar to those in the host, sug- gezting the host as the main iource: houe\ cr. longebractcatu (Orohnnchacrae) - a neb\ x nrirtx iome are found onl\ in the paras it^ suggesting from Greece.] 'Tilldenouiia 24: 49.5 1, (In Ger- ioine abilitv for gibberellin s\nthesis in the para- man.) site.) 1 an Hrzrwijk. 31. J., K-H. Linke. F. Lopez-Granados, Sweenev. E. C., R. A. Palmer and U. Pfuller. 1993. 0. A. Al-Menoufi. L. Garcia-Torres. M. C. Saxe- Cr! stallizatioii of the ribosome inactivating pro- na, J. A. C. Verltleij and A. H. Pieterse. 1994. tein ML1 from Viscum album (mistletoe) com- Seasonal changes in germination response of bur- plexed with beta-D-galactose, Journal of Molecu- ied seeds of Orobanche ctenata Forslt. Weed lar Biology 234: 1279-1281. Research 34: 369-376. (Confirming a pro- ter Borg, S. J., A. Willemson, S. A. Khalil, H. A. nounced natural cycle of germinability, during Saber, J. A. C. Verlcleij and A. H. 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HAUSTORIUM is edited by L. J. Musselman, Parasitic Plant Laboratory, Department of Biologi- cal Sciences, Old Dominion University, Norfolk, Virginia 23529 -0266 USA, electronic mail LJMlOOF at ODUVM.CC.ODU.EDU, fax 804-683-5283 and C. Parker, c/o Long Ashton Research Station, University of Bristol, Bristol, BS18 9AF, ENGLAND, fax (1275) 394007. It is prepared by John Musselman and is usually published twice yearly by Old Dominion University and funded by grant DHR-5600-G-00- 1021 -00 from the Agency for International Development. Unsigned articles and literature reviews are by the editors. Send material for publication to either editor. Complete sets of HAUSTORIUM are available for US$30 postpaid. Make checks payable to Lytton J. Musselman and drawn on an American bank. To receive your copies of HAUSTORIUM or the bibliographies via electronic mail, send a message to the email address above. Issues 21-30 are available electronically.

Haustorium 29 was mailed 2 June 1994

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