HAU STORIUM Parasitic Plants Newsletter Official Organ of the International Parasitic Seed Plant Research Group May 1997 .......................................................................................................................................... Number 32 0 0 WHAT HAPPENED TO A Review of Strigu Control in Sorghum HAUSTORIUM? and Millet was held at ICRISAT, Samanko, Mali on 27-28 May 1996. Participants from The editors apologize for the delay in publishing National Agricultural Research Programs in HAUSTORIUM 32. The good news is that we have West and Southern Africa; Universities and received support from the Food and Agriculture Research Institutes in UK, Germany and Organization for HAUSTORIUM. This has enabled us USA; as well as ICRISAT scientists from to upgrade computer capabilities and develop a home Africa and India attended the two-day meet- page. But we still very much need contributions from ing. The review was based on a series of you! And we still need long term financial support. papers which summarized and synthesized the present status of research on methodolo- gies for control of Strigu in sorghum and WE’RE ON THE WORLD millet. This was complemented by working WIDE WEB!! groups which critically reviewed ICRISAT’s past and present efforts on Strigu control HAUSTORIUM now has its own homepage! Find and made priority recommendations on us at the Old Dominion University homepage: future research needs to improve the focus www.odu.edu Select College of Sciences, the Depart- and organization of the research and collab- ment of Biological Sciences, then faculty, then Mussel- oration with existing and new partners man. At the end of the Musselman page click on (NARS, IARCs, ARIs, NGOs etc.). HAUSTORIUM. This homepage will be updated regu- larly. You can contact us electronically at: The main recommendations of the [email protected]. review included the reinforcement of ICRI- SAT’S strategy to develop integrated control methodologies; the need for ICRISAT to 0 THE SEVENTH INTERNATIONAL place more emphasis on Strigu in sorghum; SYMPOSIUM the need to enhance collaborative linkages ON PARASITIC WEEDS for strategic research especially related to better understanding of variability within Possible venues and dates for the next parasitic major Strigu spp. for developing sound weed symposium were discussed at Cordoba. Norfolk, strategies for resistance breeding and devel- Virginia was suggested as a possible site. The date is oping improved screening methodologies yet to be determined but is very tentatively planned through the use of existing bioassays and for May 1999. Suggestions and offers for sponsorship molecular marker technology; the need to are eagerly sought! develop a well-balanced, multi-disciplinary team in West Africa; and the importance of supporting the Parasitic Weeds Theme of 0 ICRISAT Strigu Review the System-wide IPM Initiative to foster col- laboration with IITA and CIMMYT. A pro- PUBLISHED BY OLD DOMINION UNIVERSITY Haustorium 32 ceedings from the review is being prepared Strobilanthes species which are common for publication by ICRISAT in 1997. sub-shrubs in the area. In India both C. cal- carata and C. neilgherrica are reported to. J. Lenne, ICRISAT, Patancheru, India be parasitic on Strobilunthes spp. (Hooker, 1850). Very little has been published on the genus since it was first described by 0 A ROOT PARASITE FROM THE Gardner in 1847 who recognized seven UPLANDS OF SRI LANKA species. Several additions have been made to the genus subsecpently and at least three During a recent visit to Sri Lanka it was are endemic to Sri Lanka. There are two possible to travel to some of the higher alti- closely related parasitic genera Aeginetia tude areas in the center of the island, where and Campbellia and the taxonomic bound- the world-famous tea industry is based. The aries between them are not clear and simi- natural sub-montane flora in the 2000-2500 larly, there is no agreement on the species m range bears a striking similarity to the limits within Christisonia. Christisonia Himalayan flora found at a similar altitude aurantiaca is considered synonymous with in Nepal some 1400 miles to the north. In C. bicolor but this is not apparent from the both habitats the majestic Rhododendron illustrations in Wight or from Gardners arboreum is a dominant tree species and the original descriptions. large species of Magnolia of the middle Himalayas are mimicked by Michelia nilagi- There appears to be almost no informa- rica in Sri Lanka. Among the sub-shrubs tion on this group of plants in modern liter- Berberis zeylanica is a reminder of the ature. There are illustrations of C. calcarata gaudy yellow flowered Himalayan species in Wight 1885 and of C. aurantiaca and C. Mahonia napaulensis which has contributed lawii in Neilgherry Plants published in so much to the genetic foundation of the 1893. Wight was also impressed by the varieties of Mahonia favored by horticultur- beauty of these plants and suggested that alist s. they could be as popular in cultivation as orchids were it not for their parasitic habit. a This tlwarf montane forest is engulfed He predicted that one day they would by cloud for large parts of the year and it is become popular horticultural subjects but to thought to intercept significant amounts of date this has not happened. precipitation. Experiments are currently underway to quantify the contribution of The stem is a flattened structure partial- this interception to the soil water balance ly submerged in the soil but appearing cob- and its importance to the water economy of bled and uneven from the numerous large the upper Mahaweli river catchment. It was flower buds on the surface. Flowers appear while inspecting the site of an experiment in singly or in small groups. They are tubular this montane forest that the striking root up to 5 cm. in length opening to a weakly parasite Christisonia bicolor was spotted. defined bilabiate mouth. The throat of the Christisonia has one of the largest and most corolla is deeply purple fading to white at spectacular flowers I have seen in the Oro- the margins. The style is very persistent banchaceae. The genus is confined to Asia with a large clavate, papillose stigma up to and most records are from south India and 75 mm broad. Styles remain erect from the Sri Lanka (the only Himalayan collection - a flattened stem after the corolla has disap- single collection from Sikkim - has been C. peared and the viscid stigma remains pendu- hookeri, interestingly) though it extends to lous with several in various stages of maturi- China in the North to Burma, the Philip- ty. Anthers are in two pairs with pines and Peninsular Malaysia in the East. pronounced spurs articulating on the tips of Clumps of Christisonia bicolor can be found the filaments at their centers. There appears among the dark understory of the mature to be no chlorophyll in any part of the forest. Trimen in the Handbook Flora of plant. The pollination biology of this pecul- Ceylon records that it is parasitic on the iar plant can only be guessed but the viscid roots of Acanthaceae. These are likely to be a Page 2 f Haustorium 32 persistent stigmata might be attractive to tative of the main sponsors, the Directorate slugs or to snails. General of Agricultural Research, Consejero de Agricultura y Pesca, Junta de Andalucia. [For beautiful line drawings of these plants, Professor Jose Cubero then treated us to a a see HAUSTORIUM 32 on the Web] thought- provoking review of the progress and content of the six symposia so far. Philip Bacon, Oxford Forestry Institute, University of Oxford, South Parks Road, The first invited lecture, presented by Oxford, UK Dan Nickrent, showed how new molecular techniques using ribosomal RNA, could be used to clarify the evolutionary and phylo- genetic relationships between and within FOURTH INTERNATIONAL different families of parasitic plants. Results WORKSHOP ON OROBANCHE have suggested a reappraisal of several of RESEARCH these relationships and confirmed many oth- ers. A number of other papers pursued the This symposium is scheduled for 23-26 same theme, using both molecular and more September 1998 in Albena, Bulgaria and is traditional cladistic techniques. These tend- sponsored by the Institute for Wheat and ed to confirm the possible separation of the Sunflower in Bulgaria. The institute is a 'agrestal' Striga asiatica from other closely leading center for Orobanche research in related taxa such as S. hirsuta and S. Zutea, sunflower. Sessions will include germination, while suggesting a relatively close relation- physiology, growth and development, resis- ship between s. hermonthica and s. aspera, tance and other topics of interest to parasi- the former perhaps representing another tic plant researchers. Albena is a small 'agrestal species' derived from the latter resort city on the beautiful Bulgarian Black (invited paper by Mohamed, Musselman and Sea coast. For further information contact others). The concept of agrestal species the Technical Secretariat for the sysymposi- might also be applied to the Old World Oro- um at fax number (359) 058 26364. banche cernualcumana which has relatively 0 recently evolved to attack New World spec- ies such as sunflower, tomato and tobacco. SIXTH INTERNATIONAL PARASITIC The separation of this pair of species, as WEEDS SYMPOSIUM well as the 0. ramosalaegyptiaca pair appeared to be justified by several of the The Sixth International Symposium was studies. A workshop devoted to the topic of successfully held in Cordoba from 16 to 18 molecular biology provided useful reminders April. About 150 delegates and their spous- of its potential but also of the need for care- es attended from at least 30 countries, and ful selection of technique to match the enjoyed what must have been the cultural objectives of the study. In the most detailed highlight of our series so far, as well as a review of the subject to date, Jose Cubero scientific programme to equal any.