Comparative Canopy Damage among Provenances of Baldcypress Associated with the Presence of Cercosporidium sequoiae (Ellis and Everth.) W.A. Baker and Partridge

Abstract

<jats:p>Seeds of <jats:italic>Taxodium distichum</jats:italic> (L.) Rich. were collected, germinated, and grown from native stands ranging from Mexico, Texas, Louisiana, Mississippi, and Alabama. Twenty-two provenance selections were planted in Summer 2004 in College Station, TX, in 36 replicated single-plant replications per block for a total of 792 trees. Below-average midsummer temperatures and above-average number of rainfall events were conducive to the development of a leaf blight associated with the presence of <jats:italic>Cercosporidium sequoiae</jats:italic> (Ellis and Everh.) W.A. Baker and Partridge. A survey conducted in Oct. 2007 rated differential defoliation responses among provenances. Selections of <jats:italic>Taxodium distichum</jats:italic> var. <jats:italic>mexicanum</jats:italic> (Gordon) from Mexico and south Texas showed defoliation rates from 89% to 96%, whereas <jats:italic>T. distichum</jats:italic> var. <jats:italic>distichum</jats:italic> from central Texas had defoliation ratings from 79% to 99%. With the exception of one family collected from the Sabinal River in Texas, the central Texas selections had similar defoliation compared with those from south Texas. Selections of <jats:italic>T. distichum</jats:italic> var. <jats:italic>distichum</jats:italic> and one selection of <jats:italic>T. distichum</jats:italic> var. <jats:italic>imbricarium</jats:italic> (Nutt.) Croom from southeastern regions (Alabama, Louisiana, Mississippi, and east Texas) showed greater tolerance to the presence of the leaf blight with 52% to 80% mean defoliation. A few individuals within these families exhibited little or no symptoms of the leaf blight. In general, those selections from high-rainfall, high-humidity areas had less defoliation associated with the presence of the leaf blight fungus, although defoliation was variable among provenances within all geographical regions. These results suggest that tolerance to defoliation from <jats:italic>C. sequoiae</jats:italic> could be included in selection criteria when choosing possible germplasm releases from <jats:italic>Taxodium distichum</jats:italic>.</jats:p>

Provenance Experiments with Baldcypress, Live Oak, and Sycamore Illustrate the Potential for Selecting More Sustainable Urban Trees

“…Trees on the Florida panhandle site were so severely infested with this pathogen during the second growing season that foliar chlorosis ratings were not attempted. Thus, the aesthetic value of taxa of Taxodium in landscapes could also be improved by selecting for greater field-level resistance to foliar pathogens such as C. sequoiae (McDonald et al 2008).…”

“…In addition to the work presented herein, preliminary screening for tolerance in provenances of Taxodium to Cercosporidium sequoiae infection (McDonald et al 2008), chronic and acute drought tolerance (Denny 2007), foliar and soil salinity exposure (Denny 2007), and alkalinity tolerance (Denny et al 2008) have been completed. Studies to assess genotypic differences in response to flooding, resulting in differential soil oxygen levels, are underway in the hopes that a relationship with knee development can be identified permitting selection of genotypes with reduced knee development.…”

Assessment of Genetic Variations of Taxodium Trees in Egypt

“…The main importance for Taxodium plants is wood, which has been economically appreciated due to its flexibility and heavily collected due to it is resistant to decay but is too soft, light, actual durable, and does not warp easily Wiemann, (2021), in addition, the author studied Characteristics and availability of commercially important woods. Currently, the Taxodium genus is separate in numerous ecosystems counting coastal wetlands and floodplains across the USA as reported by (Mitsch et al, 2013, McDonald et al, 2008, Barbuto et al, 2010. T. distichum (L.) (B. cypress) is typically wild rising in a riparian environment, or swamps (flooding) and is valuable as a landscape tree (Abdelsalam et al, 2019, Shachak et al, 2008, Schoen et al, 1991.…”

Can We Improve the Salinity Tolerance of Genotypes of Taxodium by Using Varietal and Hybrid Crosses?

“…The results indicated that most genotypes tolerate moderate levels of soil salts, but at high soil salinities, the tolerance appears to be highly genotype-dependent. While more salt tolerant, MC genotypes are generally more susceptible to Cercospora needle blight (McDonald et al, 2008). In this study, we evaluated growth and leaf nutrient changes in three Taxodium genotypes (BC, MC, and one BC • MC hybrid) exposed to acute applications of four rates of salt solution.…”