Indirect selection and clonal propagation of loblolly pine seedlings enhance resistance to fusiform rust

1989 ◽  
Vol 19 (4) ◽  
pp. 534-537 ◽  
Author(s):  
G. S. Foster ◽  
R. L. Anderson
Keyword(s):  
Loblolly Pine ◽  
Rust Resistance ◽  
Clonal Propagation ◽  
Indirect Selection ◽  
Artificial Inoculation ◽  
Fusiform Rust ◽  
Rooted Cutting ◽  
Pine Seedlings ◽  
Susceptible Control ◽  
High Degree

A population of loblolly pine (Pinustaeda L.) seedlings without fusiform rust (Cronartiumquercuum (Berk.) Miyabe ex Shirai f.sp. fusiforme) galls was developed by controlled-cross matings of parent trees with known rust resistance, and subsequent screening of the seedling offspring through artificial inoculation. The seedlings without rust galls then entered a vegetative propagation system using rooted cuttings. A second round of rust testing by artificial inoculation, using a random sample of 20 clones from the program, revealed a high degree of rust resistance (4% galled) compared with that of seedlings from either a resistant control seedlot (50% galled) or a susceptible control seedlot (81% galled). This apparently high degree of rust resistance may be due to genetic effects, rooted cutting morphology, or both.

Influence of Fertilization and Ectomycorrhizae on Loblolly Pine Growth and Susceptibility to Fusiform Rust

1983 ◽  
Vol 7 (2) ◽  
pp. 101-103 ◽  
Author(s):  
H. R. Powers ◽  
S. J. Rowan
Keyword(s):  
Loblolly Pine ◽  
Cultural Practices ◽  
Mycorrhizal Fungus ◽  
Height Growth ◽  
Pisolithus Tinctorius ◽  
Fusiform Rust ◽  
Infected Tree ◽  
Pine Seedlings ◽  
Susceptible Control ◽  
Rust Severity

Abstract The application of fertilizer and the mycorrhizal fungus, Pisolithus tinctorius, did not increase the height growth of loblolly pine seedlings during their first four years of growth. Fertilization, however, did increase the overall number of fusiform rust galls per infected tree. This increase was highly significant on the susceptible control seedlings, but was not significant on resistant Livingston Parish seedlings. This indicates that cultural practices such as fertilization can be applied to rust-resistant seedlings, such as the Livingston Parish seed source, without significantly increasing rust severity.

Monoterpene composition and fusiform rust resistance in slash and loblolly pines

1995 ◽  
Vol 25 (2) ◽  
pp. 193-197 ◽  
Author(s):  
M. Michelozzi ◽  
T.L. White ◽  
A.E. Squillace ◽  
W.J. Lowe
Keyword(s):  
Loblolly Pine ◽  
Rust Resistance ◽  
Slash Pine ◽  
Cortical Tissue ◽  
Fusiform Rust ◽  
Breeding Values ◽  
Loblolly Pines ◽  
Monoterpene Composition

Monoterpene composition of cortical tissue was analyzed in slash pine (Pinuselliottii Engelm. var. elliottii) and loblolly pine (Pinustaeda L.) clones with known breeding values for fusiform rust resistance. Trees having a relatively high content of β-phellandrene tend to be more resistant than trees with a low β-phellandrene content. Such results confirm previous data and suggest the utilization of β-phellandrene content as an aid in selecting relatively rust resistant slash and loblolly pines.

scholarly journals Early Field Growth of Loblolly Pine Rooted Cuttings and Seedlings

2000 ◽  
Vol 24 (2) ◽  
pp. 98-105 ◽  
Author(s):  
John Frampton ◽  
Bailian Li ◽  
Barry Goldfarb
Keyword(s):  
Loblolly Pine ◽  
Large Scale ◽  
Growth Traits ◽  
Volume Growth ◽  
Field Performance ◽  
Rooted Cuttings ◽  
Fusiform Rust ◽  
Rooted Cutting ◽  
Sib Families ◽  
Improvement Programs

Abstract Early growth and fusiform rust resistance of loblolly pine (Pinus taeda L.) rooted cuttings and seedlings from the same nine full-sib families established on two sites (Nassau Co., FL and Monroe Co., AL) were compared. Although site effects on growth were large, height, diameter and volume growth of the rooted cuttings and seedlings did not differ through the first six growing seasons in the field (with the exception of first year height growth at the Florida site). Fusiform rust (caused by Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp. fusiforme [Cumm.] Burds. et Snow) incidence at age 6 yr was significantly lower in the rooted cuttings than the seedlings at both the Florida site (15.6 versus 22.3 %, respectively) and the Alabama site (46. 0 versus 51.0%, respectively). In addition, correlations of full-sib family performance between (1) rooted cuttings and seedlings and (2) rooted cuttings and seedling progeny test data were positive, statistically significant and moderate to high for both growth traits and fusiform rust incidence. Thus, families or individual trees selected from seedling genetic tests in existing tree improvement programs should also perform well as rooted cuttings. These results and those from similar studies indicate that field performance of loblolly pine rooted cuttings derived from seedling hedges should not be a concern. Large-scale propagation using rooted cuttings will deliver predicted gains from the selection and deployment of elite full-sib families and clones. In addition, the use of rooted cutting planting stock may offer a further reduction in fusiform rust incidence. South. J. Appl. For. 24(2):98-105.

scholarly journals NLR Diversity and Candidate Fusiform Rust Resistance Genes in Loblolly Pine

2021 ◽  
Author(s):  
Daniel Ence ◽  
Katherine E Smith ◽  
Shenghua Fan ◽  
Leandro Gomide Neves ◽  
Robin Paul ◽  
...  
Keyword(s):  
Gene Family ◽  
Resistance Gene ◽  
Loblolly Pine ◽  
Resistance Genes ◽  
Rust Resistance ◽  
De Novo ◽  
Gene Diversity ◽  
Gene Family Evolution ◽  
Fusiform Rust ◽  
Geographic Diversity

Abstract Resistance to fusiform rust disease in loblolly pine (Pinus taeda) is a classic gene-for-gene system. Early resistance gene mapping in the P. taeda family 10-5 identified RAPD markers for a major fusiform rust resistance gene, Fr1. More recently SNP markers associated with resistance were mapped to a full-length gene model in the loblolly pine genome encoding for an NLR protein. NLR genes are one of the most abundant gene families in plant genomes and are involved in effector-triggered immunity. Inter- and intraspecies studies of NLR gene diversity and expression have resulted in improved disease resistance. To characterize NLR gene diversity and discover potential resistance genes, we assembled de novo transcriptomes from 92 loblolly genotypes from across the natural range of the species. In these transcriptomes, we identified novel NLR transcripts that are not present in the loblolly pine reference genome and found significant geographic diversity of NLR genes providing evidence of gene family-evolution. We designed capture probes for these NLRs to identify and map SNPs that stably cosegregate with resistance to the SC20-21 isolate of Cronartium quercuum f.sp. fusiforme (Cqf) in half-sib progeny of the 10-5 family. We identified ten SNPs and two QTL associated with resistance to SC20-21 Cqf. The geographic diversity of NLR genes provides evidence of NLR gene family-evolution in loblolly pine. The SNPs associated with rust resistance provide a resource to enhance breeding and deployment of resistant pine seedlings.

scholarly journals Eight-Year Field Performance of Pine Seedlings after Mycorrhizae Were Triadimefon-Inhibited in the Nursery

1996 ◽  
Vol 20 (1) ◽  
pp. 42-44
Author(s):  
W. A. Carey ◽  
W. D. Kelley
Keyword(s):  
Loblolly Pine ◽  
Field Performance ◽  
Fusiform Rust ◽  
Pine Seedlings ◽  
Mycorrhizal Development

Abstract Loblolly pine seedlings were not sprayed with a fungicide or were sprayed with triadimefon (Bayleton®) at 6 oz ai/ac or with twice or four times that rate to differentially suppress mycorrhizal development. Seedlings were planted at three sites and evaluated in the eighth year after outplanting. Fusiform rust incidence and tree heights and diameters differed significantly between nursery sources and among outplanting sites, but not between triadimefon treatments. Survival did not differ between sites, nursery sources or triadimefon treatments. South. J. Appl. For. 20(1):42-44.

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