South California Research Articles

How caterpillars avoid overheating: behavioral and phenotypic plasticity of pipevine swallowtail larvae

We tested the hypothesis that larvae of the pipevine swallowtail butterfly, Battus philenor, employ behavioral and phenotypic plasticity as thermoregulatory strategies. These larvae are phenotypically varied across their range with predominantly black larvae (southeastern USA and California) and red larvae (western Texas, Arizona) occurring in different regions. Two years of field observations in south Texas indicate that the proportion of red larvae increases with increasing daily temperatures as the growing season progresses. Larvae were also observed to shift their microhabitats by climbing on non-host vegetation and avoided excessive heat in their feeding microhabitat. Larvae of ten half-sib families from populations in south Texas and California, reared under different temperature regimes in common garden experiments, exhibited plasticity in larval phenotype, with larvae from both populations producing the red phenotype at temperatures greater than 30 degrees C and maintaining the black phenotype at cooler temperatures. However, larvae from Texas were more tolerant of higher temperatures, showing no decrease in growth rate in the highest temperature (maximum seasonal temperature) treatment, compared to the California population. In a field experiment, black larvae were found to have higher body temperatures when exposed to sunlight compared to red larvae. These results suggest that microhabitat shifts and the color polyphenism observed in pipevine swallowtail larvae may be the adaptive strategies that enable larvae to avoid critical thermal maximum temperatures.

The Cenozoic hermatypic corals in the eastern Pacific: History of research

Studies of hermatypic corals in the eastern Pacific have mainly focused on Recent species, and relatively few of these works have studied fossil corals. The purpose of the present contribution is to provide a comprehensive synthesis on Cenozoic hermatypic coral studies that will serve: a) to identify gaps in our understanding about the Cenozoic evolution of eastern Pacific hermatypic fauna, and b) to be used as a baseline for future work in the region. Our knowledge regarding the eastern Pacific fossil coral fauna has increased gradually since 1864. A total of 151 coral species including synonyms have been recorded in the region. The species richness increases from Paleocene to Oligocene followed by a loss of species towards the Pleistocene, though to some extent biodiversity estimates are affected by sampling intensity. Fossil-bearing units are spatially restricted to Washington-Seattle, south and central California, Gulf of California and Chiapas, and there is a lack of outcrops in western México and Central America. In general, fossil coral studies have been sporadic, incidental in nature, and restricted to species descriptions, faunal lists and geographic affinities. The relative lack and nature of the hermatypic fossil studies in the region have directly affected our understanding about the origin of the modern eastern Pacific coral fauna and its evolutionary history. Studies regarding to taxonomy and systematics, and detailed spatio–temporal community dynamics, are essential for understanding the evolution of the fauna.

UPDATE ON POWDERY MILDEW RESISTANCE SCREENING IN WATERMELON

Powdery mildew has been reported on Citrullus lanatus in Africa and Europe for the past 9 years, and in the United States for the past 6 years. During this time, it has occurred in the main watermelon production areas in the U.S. and has been documented in nine states (South Carolina, Georgia, Florida, Oklahoma, Texas, Maryland, New York, Arizona, and California). This is of great concern to the watermelon industry since powdery mildew is difficult to control and can have a severe impact on yield and fruit quality due to loss of photosynthetic area and sunscald. Finding resistant C. lanatus germplasm is needed for the development of commercial varieties containing this resistance. This report summarized the status of an ongoing project to screen the entire USDA–ARS C. lanatus germplasm collection. Currently, the collection is being screened for race 1 and race 2 Podosphaera xanthii (syn. Sphaerotheca fuliginea auct. p.p.), the causal agent of powdery mildew in C. lanatus in the United States. Resistance genes appear to exist for both races and the genes conferring resistance to race 1 appear to be different than race 2 resistance genes. Allelism tests are currently in process to determine the number of resistance genes present.

UPDATE ON POWDERY MILDEW RESISTANCE SCREENING IN WATERMELON

Powdery mildew has been reported on Citrullus lanatus in Africa and Europe for the past nine years, and in the United States for the past 6 years. During this time, it has occurred in the main watermelon production areas in the U.S. and has been documented in nine states (South Carolina, Georgia, Florida, Oklahoma, Texas, Maryland, New York, Arizona, and California). This is of great concern to the watermelon industry since powdery mildew is difficult to control and can have a severe impact on yield and fruit quality due to loss of photosynthetic area and sunscald. Finding resistant C. lanatus germplasm is needed for the development of commercial varieties containing this resistance. This report summarized the status of an ongoing project to screen the entire USDA–ARS C. lanatus germplasm collection. Currently, the collection is being screened for race 1 and race 2 Podosphaera xanthii (syn. Sphaerotheca fuliginea auct. p.p.), the causal agent of powdery mildew in C. lanatus in the United States. Resistance genes appear to exist for both races and the genes conferring resistance to race 1 appear to be different than race 2 resistance genes. Allelism tests are currently in process to determine the number of resistance genes present.

Allelopathic Effects of Volatile Monoterpenoids Produced by Salvia leucophylla: Inhibition of Cell Proliferation and DNA Synthesis in the Root Apical Meristem of Brassica campestris Seedlings

Salvia leucophylla, a shrub observed in coastal south California, produces several volatile monoterpenoids (camphor, 1,8-cineole, beta-pinene, alpha-pinene, and camphene) that potentially act as allelochemicals. The effects of these were examined using Brassica campestris as the test plant. Camphor, 1,8-cineole, and beta-pinene inhibited germination of B. campestris seeds at high concentrations, whereas alpha-pinene and camphene did not. Root growth was inhibited by all five monoterpenoids in a dose-dependent manner, but hypocotyl growth was largely unaffected. The monoterpenoids did not alter the sizes of matured cells in either hypocotyls or roots, indicating that cell expansion is relatively insensitive to these compounds. They did not decrease the mitotic index in the shoot apical region, but specifically lowered mitotic index in the root apical meristem. Moreover, morphological and biochemical analyses on the incorporation of 5-bromo-2'-deoxyuridine into DNA demonstrated that the monoterpenoids inhibit both cell-nuclear and organelle DNA synthesis in the root apical meristem. These results suggest that the monoterpenoids produced by S. leucophylla could interfere with the growth of other plants in its vicinity through inhibition of cell proliferation in the root apical meristem.

Presentation of the Distinguished Achievement Award 2003 to Ramón and José David Saldívar and Sonia Saldívar-Hull

PRESENTATIO N OF THE D is tin g u is h e d A c h ie v e m e n t A w a r d 2003 t o R am ón a n d J o s é D a v id S a ld iv a r a n d S o n ia S a l d í v a r - H u l l K r i s t a C o m e r Little work has been as important to recent thinking about the “bor­ ders” of western literary as that of Chicano/a studies, and few critics have been as influential in establishing the parameters of that field as have been the Saldivar siblings. From them, and from the field more broadly conceived, western literary studies has learned a great deal. If, in some fundamental way, many ofthe most prominent ofChicano and Chicana writers and critics, beginning at least with Paredes, have been “regionalists,” they have been so in terms which reveal very dif­ ferent spatial imaginations and cultural geographies than those typically governing especially (but not only) South Texas and California. Those differences have had every consequence. For example, while western studies has recognized the signifi­ cance of figures like Américo Paredes to the history and culture of the American West and Texas— in fact, Paredes received this very award in 1985— it has taken someone with Ramon’s institutional stature and poststructural credentials, not to mention the existence of Chicano/a studies as a field, to make the case Paredes himself tried to make, and to less effect: that the social groups incorporated into the nation proper after the Mexican American War carry upon their historical backs the memories of their Mexican pasts, and this fact continually re-creates the presence of “Greater Mexico” within U.S. borders today. O f particular importance is the light it sheds on the Greater Mexican structures of feeling that animate so many features of daily life in western spaces, whether or not one is mexicano. With different spatial orientations have come different genealogical traditions from which to conceptualize “regions,” expanding the critical resources at our analytic disposal. O f all the Saldivars, José David has most explicitly situated his work, especially that of Border Matters (1997), in dialogue with mythol­ ogies of the American West. His focus upon the cultural borderlands which both divide and unite the United States and Mexico identifies W e s t e r n A m e r i c a n L i t e r a t u r e 4 0 .3 ( F a l l 2 0 0 5 ): 3 4 2 - 4 3 . S a l d i v a r P l e n a r y not only a dynamic and transnational ethnoregional formation, but it artfully addresses the border as a barometer of U.S. foreign policy. Since 9/11, the worries José David raised in Border Matters about unconstitionalities levied against people deemed “alien” have unfortunately proven truer than any of us would have wished or foreseen. Borderlands military operations have in some ways offered a case study in organiz­ ing the so-called war against terrorism, and again, the border reveals itself to be buried in the center of power struggles. By preserving in his work the internationalism of early Chicano/a studies and applying that perspective to contemporary political “hot spots” like the U.S./Mexican border, José David offers any of us doing regional studies today one of the more extended examples in cultural studies of how to theorize the interface between local and global while incorporating matters of politi­ cal economy and state-sponsored violence. As Sonia makes so clear in Feminism on the Border (2000), gender issues and power hierarchies always bear intimately on individual life stories as well as literary and scholarly production. Like Gloria Anzaldúa and Cherríe Moraga, Sonia’s interests are nothing less than formulating a global theory of power for women. As is true for most Chicana theo­ rists, the trope of “borders” figures largely here; but in Sonia’s hands, it is more insistently a political trope...

Multi-objective trade-offs for fuel cell-based auxiliary power units: case study of South California Air Basin

Auxiliary power units (APUs) are energy devices that complement the main internal combustion engine of a vehicle providing power for the non-propulsion needs. There are several goals or objectives that need to be achieved for designing and operating fuel cell-based APUs. The system should have as high efficiency as possible, but also be economically viable with cost or profits competitive with the existing technology. Not only should the environmental impacts of the chemicals released during the process be as low as possible, but also the human health impact has to be minimum. This becomes an extremely challenging multi-objective problem and its solution leads to the quantification of the trade-offs between the different objectives. The fact that these multiple objectives are often conflicting in nature and can have completely different trends with respect to multiple process variables makes the representation and analysis of the trade-off information an extremely formidable task. The solution of the multi-objective optimization of the system, which comprehends sensitivity analysis, payoff table and optimal trade-off surfaces, is illustrated. The case study that was chosen for the simulations is South California Air Basin and the assumptions that were taken to model this region are briefly discussed.

Absorption, translocation and allocation of glyphosate in resistant and susceptible Chilean biotypes of Lolium multiflorum

Glyphosate [N‐(phosphonomethyl) glycine] is currently the most important non‐selective, wide‐spectrum herbicide used worldwide. Introduced in 1974, glyphosate was initially a non‐crop herbicide and plantation crop herbicide, although it is now widely used in no‐till crop production and, more recently, for weed control in herbicide‐resistant transgenic crops, such as maize, soybean and cotton (Baylis 2000; Caseley & Copping 2000). Despite its widespread and long‐term use, no case of evolved resistance to glyphosate was documented until 1996 (Pratley et al. 1996). Since then, a few other cases have been reported. To date, evolved resistance to glyphosate has been identified and documented in Lollium rigidum in Australia (Powles et al. 1998; Pratley et al. 1999), Eleusine indica in Malaysia (Lee & Ngim 2000), and L. rigidum in South Africa and California (USA), and Conyzia canadensis in Delawere (USA) (Van Gessel 2001). Also, accessions of L. rigidum from South Africa and California have been reported to resist glyphosate (Heap 2001). In Chile, the first case of glyphosate‐resistance in Lolium multiflorum was reported in 1999 and documented in 2003 (Pérez & Kogan 2003). This case was the result of an intensive selection pressure caused by the continuous applications of glyphosate in fruit orchards over 8–10 years. The present study is a first approach to elucidating the mechanism involved in the resistance of one biotype of L. multiflorum selected in Chilean orchards.

The Christian Right in American politics: marching to the millennium

From first rumblings of Moral Majority over twenty years ago, Christian Right has been marshalling its forces and maneuvering its troops in an effort to re-shape landscape of American It has fascinated social scientists and journalists as first right-wing social movement in postwar America to achieve significant political and popular support, and it has repeatedly defied those who would step up to write its obituary. In 2000, while many touted demise of Christian Coalition, broader undercurrents of movement were instrumental in helping George W. Bush win GOP nomination and White House. Bush repaid that swell of support by choosing Senator John Ashcroft, once movement's favored presidential candidate, as attorney general. The Christian Right in American Politics, under direction of three of nation's leading scholars in field of religion and politics, recognizing movement as a force still to be reckoned with, undertakes important task of making an historical analysis of Christian Right in state politics during its heyday, 1980 to millennium. Its twelve chapters, written by outstanding scholars, review impact and influence of Christian Right in those states where it has had its most significant presence: South Carolina, Virginia, Texas, Florida, Michigan, Iowa, Kansas, Minnesota, Colorado, California, Maine, and Oregon and Washington. Since 1980, scholars have learned a good deal about social characteristics, religious doctrine, and political beliefs of activists in and supporters of Christian Right in these states, and each contribution is based on rigorous, dispassionate scholarship. The writers explore gains and losses of movement as it attempts to re-shape political landscapes. More precisely, they provide in-depth descriptions of resources, organizations, and group ecologies in which Christian Right operates-the distinct elements that drove movement forward. As editors state, the Christian Right has been engaged in a long and torturous 'march toward millennium,' from outsider status into thick of American politics. Those formative years, 1980-2000, are essential for any understanding of this uniquely American social movement. This rigorous analysis over many states and many elections provides clearest picture yet of goals, tactics, and hopes of Christian Right in America.

Locating the sources of an invasive pest, grape phylloxera, using a mitochondrial DNA gene genealogy.

Range expansions through human introductions have increased with global commerce and have led to the extinction of native species, alterations in community structure and pest status of the invasive species. Inferring the evolutionary history of invasive species can help to build a firmer footing for management tactics. This study used mitochondrial DNA (mtDNA) sequence comparisons of samples collected from the native and introduced ranges of a pest herbivore of cultivated grapes, grape phylloxera (Daktulosphaira vitifoliae Fitch, Phylloxeridae) to infer the sources and pattern of introductions into worldwide viticulture. Introductions into viticulture from its native North American range first occurred in the mid-19th century. The pattern of spread has suggested a focus of introduction into France, but independent introductions may have occurred elsewhere. The results show that the introduced population represents a limited subsample of the native genetic diversity. The data suggest that most grape phylloxera in viticulture, including all European, have originated in the northeastern USA where the grape species Vitis riparia dominates. There was evidence for independent introductions into South Africa and California. Most California haplotypes were most closely related to native grape phylloxera from the Atlantic Coast on V. vulpina. It is likely that subsequent spread from California into Australia, New Zealand and Peru has occurred.

A comparison of tectonic ambient shear stress value in China with that in western USA

A method is proposed to estimate average tectonic ambient shear stress value for a region. Thus the average stress values of 19 regions in western USA, and 43 regions (each region is 10°×10°) in Chinese mainland and its surroundings have been obtained. The data of 15 993 earthquakes are from the Internet Centroid Moment Tensor solution made by Harvard University from 1997 to 1999. The results demonstrate that there are highest average stress values in the regions of south California of USA and its off coast sea, reach to 12.0 MPa and 13.7 MPa respectively, then gradually decrease toward north, south, and east. The lowest value is 8.7 MPa and 63% of highest value. The average stress values in northern Xinjiang and in the Chayu region of Tibet are 17.2 and 12.9 MPa respectively. They are highest values in China and higher than USA’s. The average stress value in North China, Yunnan, Sichuan, Taiwan is similar to south California of USA. The average stress value in South-North Seismic zone is about 13 MPa, a little higher than south California. The distribution of average stress value for two important regions provides basic data for geology. These results are useful to research earthquake activity background and attenuation relation of strong ground motion parameters (e.g. peak acceleration and response spectra).

Implicit randomness in earthquakes

Analytical number theory for two integers chosen at random provides a numerical method to estimate π value. An analysis of three datasets of earthquakes including earthquakes occurring in mainland China, South California, and all over the world, thus allowed us to estimate π with less than 3.0% relative deviation. The complexity of earthquakes is expressed by implicit randomness and characteristics of seismicity. If other physical precursors were not taken into account, two or more earthquakes would be correlative with one another, or an earthquake could be partly predictable on the basis of the event sequence itself, with a ratio of about 40% at most.

建築・まちづくり等教育手法をベースにした総合的な学習と国際交流授業 : 南カリフォルニアと仙台近郊との事例を中心に

We started a design besed volunteer group called architecture and children network of Sendai to support the children for developing their creativity since 1993. We have relationship between schools in South California and study the methodology of city building education. This is a research of developing curriculum for school education through the methodology of architecture and city building education. We also challenge the video conference between schools around Sendai area and South California. We can find that students create their original Ideas and sympathize another side of the world through the video conference.

Platelet aggregation inhibition with glycoprotein IIb--IIIa inhibitors.

Inhibitors of the platelet receptor glycoprotein (GP) IIb--IIIa are a novel and potent class of antithrombotic drugs for the management of patients with non-ST-segment elevation acute coronary syndromes (ACS) and those undergoing percutaneous coronary intervention (PCI). Pharmacodynamic studies with three currently approved agents in this class (abciximab [ReoPro, Centocor, Inc., Malvern, Pennsylvania, and Eli Lilly & Company, Indianapolis, Indiana]; eptifibatide [INTEGRILIN, COR Therapeutics, Inc., South San Francisco, California, and Key Pharmaceuticals, Inc., Kenilworth, New Jersey]; and tirofiban HCI [Aggrastat, Merck & Co., Inc., Whitehouse Station, New Jersey]) all sought to identify dosing regimens that would establish and maintain >80 % inhibition of ex vivo platelet aggregation throughout the duration of intravenous infusion. Direct comparison of these prior studies is difficult, however, because the assays used different anticoagulants (sodium citrate [abciximab, tirofiban HCI] or D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone [PPACK] [eptifibatide]) and different concentrations of the platelet agonist adenosine diphosphate (ADP) (5 micromol [tirofiban HCI] or 20 micromol [abciximab, eptifibatide]). More recent work has attempted to overcome these limitations by using similar assay conditions for all GP IIb--IIIa inhibitors. These studies have indicated that the concentrations of all three agents required to provide the targeted effect for platelet inhibition are considerably higher in the presence of an anticoagulant that does not chelate calcium ions (e.g., heparin or PPACK) than in the presence of calcium-chelating anticoagulant (i.e., sodium citrate). Of the three currently approved GP IIb--IIIa inhibitors, eptifibatide is the only agent whose approved dosing is based on an ex vivo platelet aggregation assay that uses such an anticoagulant. Additionally, Kereiakes et al. have recently reported that the high levels of platelet inhibition (>80 %), using PPACK as an anticoagulant and ADP (20 micromol) as an agonist, are more consistently achieved with the approved dosing regimen of eptifibatide. The antiplatelet effect of abciximab showed more interpatient variability, whereas the median inhibition of ex vivo platelet aggregation with the approved dosing regimen for tirofiban HCl was <80 % at almost all time points during drug infusion.

Management of patients with non-ST-segment elevation acute coronary syndromes: insights from the PURSUIT trial.

The glycoprotein (GP) IIb-IIIa inhibitor eptifibatide (INTEGRILIN, COR Therapeutics, Inc., South San Francisco, California, and Key Pharmaceuticals, Inc., Kenilworth, New Jersey) is a novel and highly potent antithrombotic agent indicated for the management of patients with non-ST-segment elevation acute coronary syndromes (ACS) and those undergoing percutaneous coronary intervention. The approval of eptifibatide for non-ST-segment elevation ACS was based on the positive results of the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial. With enrollment of almost 11,000 patients, not only is the PURSUIT trial the largest trial of a GP IIb-IIIa inhibitor to date, but it is also the largest clinical study ever conducted in patients with non-ST-segment elevation ACS. The key feature of the PURSUIT trial is that patient management closely resembled standard clinical practice, because decisions about the use and timing of invasive cardiac procedures were made by the individual physicians rather than being prespecified in the study protocol. Eptifibatide therapy was associated with a significant reduction in the incidence of the primary endpoint--a composite of death or myocardial infarction at 30 days (14.2 vs. 15.7% in the placebo group; p = 0.042). Of importance is the fact that the beneficial effect of eptifibatide was independent of the management strategy pursued during study drug infusion (invasive or conservative), and it was achieved with few major safety concerns. These findings demonstrate that the use of eptifibatide should be considered for all patients presenting with signs and symptoms of intermediate- to high-risk non-ST-segment elevation ACS.

Ocean-Atmosphere Circulation and Global Climate

In recent years the meaning of the term ‘El Niño’ has been the subject of much confusion in the media. It has been widely used in television, radio and news reports usually in relation to weather phenomena such as periods of heavy rainfall in western South America and California, and droughts in Australia and Indonesia. The phenomenon of El Niño, however, is part of a much larger element of the world climate system known as the ‘El Niño-Southern Oscillation’ (ENSO). When ENSO events occur, together with intervening La Niña episodes, they affect almost two-thirds of our planet. They represent an enormously complex atmosphere-ocean feedback process that is often erratic and extreme and which also often triggers episodes of flood and drought.

A Voyage to California, the Sandwich Islands, &amp; Around the World in the Years 1826-1829 by Auguste Duhaut-Cilly

A Voyage to California, the Sandwich Islands, & Around the World in the Years 1826-1829. By Auguste Duhaut-Cilly Translated and edited by August Fruge and Neal Harlow. (Berkeley: University of California Press. 1999. Pp. xxxii, 254. $29.95.) The eyewitness accounts of visitors and travelers are a significant source of historical understanding and perspective. This volume is a wonderful example of this genre of historical observation, both in its subject matter and in the perceptive commentary of its author. While this work has been known in the original French, as well as in other translations, including one quite literal and abbreviated English version published in the California Historical Society Quarterly in 1929, this new English translation presents Duhaut-Cilly's narrative with freshness and cogency. August Duhaut-Cilly was born at the dawn of the French Revolution in 1790 and began service in the French navy shortly before his seventeenth birthday. For seven years, from 1807 until 1814, he sailed on French ships and fought in sea battles off the coast of Europe and in the Atlantic and Indian Oceans, ultimately being made a knight of the Legion of Honor. With the advent of peace, he left naval service and spent the next five years applying his maritime experience to various voyages for the merchant marine, including the journey around the world which he chronicled in this volume. He spent the final twenty years of his life in France as a private citizen until his death in 1849. This work contains the author's preface and introduction followed by twenty-three chapters which narrate the journey from France around Cape Horn to the west coast of South America, Mexico, and Baja California, along the length of Alta California as far as the Russian settlement at Fort Ross, across the Pacific to the Hawaiian Islands, to the south coast of China, and finally home to France. Much of the narrative treats Duhaut-Cilly's experiences and observations in Mexican California at a complex and crucial moment in the region's history. Accompanying the text are eleven black-and-white illustrations, four by Duhaut-Cilly which add to the authentic tone of the eyewitness account. This rich primary source material is preceded by an editors' introduction which provides textual history and criticism, a review of the cast of characters and the context of the voyage, and reflections on Duhaut-Cilly's unique perspective on the experience of Mexican California, both secular and ecclesiastical, on the eve of the secularization of the Franciscan missions. …

Geology of the South Oakley Gas Field and California's Largest Gas Well, Contra Costa County, California

Geology of the South Oakley Gas Field and California's Largest Gas Well, Contra Costa County, California

Biodiversity Hotspots in the Mediterranean Basin: Setting Global Conservation Priorities

Due to the current species extinction crisis, there is an urgent need to identify the most threatened areas of exceptionally high biodiversity and rates of endemism (i.e., hotspots; Mittermeier et al. 1998; Myers 1988; Reid 1998). Conservation strategies represent a crucial issue in the mediterranean biome because this area, which represents only 2% of the world's surface, houses 20% of the world's total floristic richness (Medail & Quezel 1997). Myers initially (1988, 1990) defined 14 hotspots in the tropical biome and four in mediterranean bioclimates (southwestern Australia, Cape Region of South Africa, California, and part of Chile). Like the four other mediterranean areas, the Mediterranean Basin is one of the world's major centers for plant diversity, where 10% of the world's higher plants can be found in an area representing only 1.6% of the Earth's surface (Medail & Quezel 1997). The prominent role played by these areas as reservoirs for plant biodiversity has been emphasized by Myers (1990). He hesitated, however, to group the whole Mediterranean Basin into one single hotspot because it covers such a large surface area, and insufficient data were available for certain regions. In this context, Medail and Quezel (1997) performed a global survey of plant richness and endemism to more precisely define hotspots in the Mediterranean Basin; they identified 10 hotspots. Three main approaches, however, have been taken in recent studies performed by international conservation organizations to define priority conservation areas in the Mediterranean Basin.

Fusarium subglutinans f. sp. Pini represents a distinct mating population in the gibberella fujikuroi species complex

Fusarium strains in the Gibberella fujikuroi species complex cause diseases on a variety of economically important plants. One of these diseases, pitch canker of Pinus spp., is caused by strains identified as Fusarium subglutinans f. sp. pini. Fertile crosses were detected between F. subglutinans f. sp. pini strains from South Africa, California, and Florida. F. subglutinans f. sp. pini strains were not cross-fertile with the standard tester strains of six of the seven other mating populations of G. fujikuroi. Sporadic perithecia with ascospores were obtained in two crosses with the mating population B tester strains. These perithecia were homothallic, and the ascospores derived from these perithecia were vegetatively compatible with the mating population B tester strain parent. We concluded that fertile F. subglutinans f. sp. pini isolates represent a new mating population (mating population H) of G. fujikuroi and that they belong to a unique biological species in a distinct taxon.