Increasing Southern Pine Timber Production Through Tree Improvement

1977 ◽  
Vol 1 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Bruce Zobel
Keyword(s):  
Rust Resistance ◽  
First Generation ◽  
Tree Improvement ◽  
Breeding Strategy ◽  
Short Term ◽  
Timber Supply ◽  
Major Objective ◽  
Breeding Programs ◽  
Fusiform Rust ◽  
Tree Form

Abstract Increasing pressures on the pine timber supply in the South make it mandatory to find ways to increase the inventory. One effective way is through tree improvement. A major objective is to improve adaptability and maintain a broad genetic base, needed both for short-term development for marginal sites and for long-range breeding programs. Results have been good, with a number of specialty orchards already established. Accomplishments through tree improvement are: (1) volume increases varying from 10 to 30 percent for first-generation orchards, depending on selection intensity, roguing methods, and breeding strategy; (2) improvement in tree form, especially straightness; (3) proof that specific gravity of wood is strongly inherited; and (4) gains in fusiform rust resistance up to 40 percent in heavily infected areas.

Predicted Genetic Gains from one Generation of Slash Pine Tree Improvement

1989 ◽  
Vol 13 (1) ◽  
pp. 51-56 ◽  
Author(s):  
G. R. Hodge ◽  
T. L. White ◽  
G. L. Powell ◽  
S. M. De Souza
Keyword(s):  
First Generation ◽  
Pinus Elliottii ◽  
Tree Improvement ◽  
Slash Pine ◽  
Growth And Yield ◽  
Yield Model ◽  
Individual Tree ◽  
Fusiform Rust ◽  
Pine Tree ◽  
Growth And Yield Model

Abstract Gains over unimproved seed for progeny from first generation--un-rogued, first generation--rogued, and one and one-half generation orchards of slash pine (Pinus elliottii var. elliottii) for individual tree volume at 15 years are predicted to be 10%, 15%, and 19%, respectively. Rustinfection of orchard progeny on sites where unimproved material incurs 50% infection are predicted to be 49%, 41%, and 35% for the three orchard types. Using a growth and yield model that incorporates fusiform rust, gains in individual tree volume and increased rust resistance were combinedto estimate effects on per acre yields. Percent volume per acre gains are predicted to be 7.0%, 13.2%, and 18.0% for the three orchard types. Collection and deployment of the most rust resistant seed to high rust hazard sites raises the gain on these sites and becomes increasingly beneficialas the rust hazard increases. South. J. Appl. For. 13(1): 51-56.

scholarly journals Two-Stage Selection in Slash Pine Produces Good Gains in Fusiform Rust Resistance

1996 ◽  
Vol 20 (3) ◽  
pp. 143-147 ◽  
Author(s):  
Earl R. Sluder
Keyword(s):  
Combining Ability ◽  
Rust Resistance ◽  
First Generation ◽  
Diallel Cross ◽  
Slash Pine ◽  
Breeding Value ◽  
Rust Disease ◽  
Fusiform Rust ◽  
Improvement Programs ◽  
Half Diallel

Abstract The best 6 of 21 progeny-tested first-generation slash pine selections were crossed in a half diallel to study inheritance patterns of their superior fusiform rust resistance (5 trees) and height (1 tree). Their six first-test progenies were duplicated and included in the study. These two groups of progenies, along with two commercial check lots, were planted on an Upper Coastal Plain and a Flatwoods site in Georgia. At age 10 yr, the 15 progenies in the half diallel averaged 23% rust-infected compared with 54% for the check lots. First-test progenies averaged 30% infected. For percentage infection, the six parents differed in general combining ability (GCA) (0.01 > P > 0.001) on both test sites and in specific combining ability (0.05 > P > 0.01) on one site. GCA variation for height was significant (0.05 > P > 0.01) on one site. The parent selected for height had the highest breeding value for height at age 10 yr. These results show that resistance to the fusiform rust disease, a serious problem in management of the species, can be improved in slash pine. These 6 parents and their 15 progenies in the half-diallel cross are a good source of rust resistance genes for use in slash pine improvement programs. South. J. Appl. For. 20(3):143-147.

scholarly journals How to reach a higher selection plateau with optimal contribution selection and compensatory mating?

2021 ◽  
Author(s):  
Tiret Mathieu ◽  
Pégard Marie ◽  
Sánchez Leopoldo
Keyword(s):  
Genetic Gain ◽  
Random Mating ◽  
Snp Array ◽  
Breeding Strategy ◽  
Genetic Response ◽  
Short Term ◽  
Breeding Programs ◽  
Trade Off ◽  
Study Case

AbstractIn breeding programs, balancing short-term genetic gain and loss of diversity per generation is essential to sustain a long-term genetic response. Depending on the dynamic of the species, the acceptable trade-off will be different. One of the most common and successful tools to achieve this management is the Optimal Contribution Selection (OCS), which readily mathematically formulate the trade-off between genetic gain and coancestry. However, OCS only accounts for the next generation gain and diversity, which can lead to suboptimality given the uncertainties of random mating and segregation. In this paper, we have extended the OCS by conveniently integrating a way to promote certain parental pairs, so that this method can account for the next t+2 generation. In the study case of Populus nigra, fully phenotyped and SNP array genotyped, we have shown that (i) a non negligible part of the long-term success of a breeding strategy depends on the implemented mating strategy, and (ii) favoring a compensatory mating can accelerate the selection without compromising the future diversity.

scholarly journals A New Breeding Strategy towards Introgression and Characterization of Stay-Green QTL for Drought Tolerance in Sorghum

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 598
Author(s):  
Nasrein Mohamed Kamal ◽  
Yasir Serag Alnor Gorafi ◽  
Hanan Abdeltwab ◽  
Ishtiag Abdalla ◽  
Hisashi Tsujimoto ◽  
...  
Keyword(s):  
Phenotypic Expression ◽  
Phenotypic Selection ◽  
Breeding Strategy ◽  
Stay Green ◽  
Breeding Programs ◽  
The Public ◽  
Drought Tolerant ◽  
Selection Step ◽  
The Cost

Several marker-assisted selection (MAS) or backcrossing (MAB) approaches exist for polygenic trait improvement. However, the implementation of MAB remains a challenge in many breeding programs, especially in the public sector. In MAB introgression programs, which usually do not include phenotypic selection, undesired donor traits may unexpectedly turn up regardless of how expensive and theoretically powerful a backcross scheme may be. Therefore, combining genotyping and phenotyping during selection will improve understanding of QTL interactions with the environment, especially for minor alleles that maximize the phenotypic expression of the traits. Here, we describe the introgression of stay-green QTL (Stg1–Stg4) from B35 into two sorghum backgrounds through an MAB that combines genotypic and phenotypic (C-MAB) selection during early backcross cycles. The background selection step is excluded. Since it is necessary to decrease further the cost associated with molecular marker assays, the costs of C-MAB were estimated. Lines with stay-green trait and good performance were identified at an early backcross generation, backcross two (BC2). Developed BC2F4 lines were evaluated under irrigated and drought as well as three rainfed environments varied in drought timing and severity. Under drought conditions, the mean grain yield of the most C-MAB-introgression lines was consistently higher than that of the recurrent parents. This study is one of the real applications of the successful use of C-MAB for the development of drought-tolerant sorghum lines for drought-prone areas.

Sex Differences in Green Ash

1979 ◽  
Vol 3 (4) ◽  
pp. 173-174
Author(s):  
John T. Talbert ◽  
Robert D. Heeren
Keyword(s):  
Sex Differences ◽  
First Generation ◽  
Tree Improvement ◽  
Fraxinus Pennsylvanica ◽  
Green Ash ◽  
Improvement Program ◽  
Male And Female ◽  
Sufficient Variation ◽  
Natural Stands ◽  
Male Superiority

Abstract A disproportionately large number of first-generation selections from natural stands of green ash (Fraxinus pennsylvanica Marsh.) have been male. A study was undertaken to determine if male and female green ash differed in several important economic characteristics. Only straightness differences could be shown to be statistically significant, and, even for this trait, several opinions were needed to detect male superiority. Sufficient variation should exist in natural stands to allow inclusion of superior individuals of both sexes in a tree-improvement program.

scholarly journals Optimization of Pollen Germination in Tectona grandis (Teak) for Breeding Programs

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 908
Author(s):  
Ana Hine ◽  
Alejandra Rojas ◽  
Lorenzo Suarez ◽  
Olman Murillo ◽  
Mario Espinoza
Keyword(s):  
Latin American ◽  
Pollen Viability ◽  
Tree Improvement ◽  
Quality Analysis ◽  
High Price ◽  
Breeding Programs ◽  
Pollen Quality ◽  
Latin American Region ◽  
Improvement Programs ◽  
Operational Activities

Teak has become one of the most widely planted species in tropical regions of the world, given its high price for its timber in international markets. This has motivated the development of tree improvement programs in the Latin American region and in the tropical world in general. The latest advances have achieved clonal forestry at an operational scale. Recently, important efforts are being made to advance towards the next breeding generation, since knowledge about floral biology and pollen management have become important issues. A breeding program is being developed through the Tree Improvement Cooperative GENFORES—a vinculation model between the academy and forestry companies that was initiated in Costa Rica and now involves six Latin American countries. In order to advance into the next breeding generations, building capacities in topics such as pollen banks requires pollen quality, thus enabling the exchange of pollen among cooperative members. Pollen fertility studies are of considerable value in breeding programs, in order to determine pollen viability and germination in collections of genotypes, before going into mating operational activities. In this study, we optimized pollen quality analysis protocols in terms of the viability and germination of fresh teak pollen. Results of this research show that 90% viability and 28% germination can be achieved in fresh pollen grains, both inside and outside the anther, previously dehydrated in silica gel for 2 to 4 h (40% and 33% humidity, respectively). Brewbacker and Kwack (BK) medium at 10% of its salts + 10% sucrose and at a pH of 7 must be used as the germination medium. It is possible to evaluate teak pollen quality using the parameters defined in this study, which will in turn allow pollen management and purification, providing an opportunity for carrying out controlled crosses at an operational scale as part of teak breeding programs.

Identification of stem rust and leaf rust resistance genes in Amagalon oats

2001 ◽  
Vol 52 (10) ◽  
pp. 1011 ◽  
Author(s):  
K. N. Adhikari ◽  
R. A. McIntosh
Keyword(s):  
Leaf Rust ◽  
Stem Rust ◽  
Rust Resistance ◽  
Recessive Gene ◽  
Leaf Rust Resistance ◽  
Leaf Rust Resistance Gene ◽  
Breeding Programs ◽  
Sensitivity Tests ◽  
Unique Source ◽  
Leaf Rust Resistance Genes

Studies were undertaken to identify the genes conferring stem rust and leaf rust resistances in Amagalon and to determine the usefulness of this line as a source of rust resistance in oat breeding programs. Amagalon was crossed with certain rust-resistant and rust-susceptible lines and segregating populations were tested with pathotypes of Puccinia graminis avenae and P. coronata avenae. Tests with the widely virulent P. graminis avenae pt 94+Pg-13 indicated that resistance in Amagalon was governed by the complementary recessive gene complex known as Pg-a. This hypothesis was further substantiated by temperature sensitivity tests and by a test of induced susceptibility to stem rust, known to be unique to lines possessing Pg-a. However, Amagalon yielded a unique source of resistance to leaf rust that was effective against current pathotypes of P. coronata avenae in Australia. This gene, assumed to be Pc91, was inherited independently of a second leaf rust resistance gene present in cv. Culgoa. It was concluded that Amagalon is a useful source of resistance to leaf rust that should be used in combination with other genes for resistance to prolong its effectiveness.

A mean-variance approach to short-term timber selling and forest taxation under multiple sources of uncertainty

1993 ◽  
Vol 23 (4) ◽  
pp. 573-581 ◽  
Author(s):  
Markku Ollikainen
Keyword(s):  
Interest Rate ◽  
Real Interest Rate ◽  
Independent Random Variables ◽  
Multiple Sources ◽  
Short Term ◽  
Timber Supply ◽  
Sources Of Uncertainty ◽  
Comparative Static Analysis ◽  
Mean Variance ◽  
Variance Approach

The effects of forest taxation on timber supply under the double uncertainty of real interest rate and future timber price are analyzed in a mean-variance framework. If future timber price and interest rate are independent random variables, there exists an asymmetry between lenders and borrowers, as there is in the single interest rate uncertainty case. Borrowers cut more and lenders cut less as a response to double uncertainty relative to single price uncertainty. If timber price and interest rate are correlated, the sign of the covariance is crucial for the interpretation of the optimality conditions and for the comparative static analysis results. If covariance is negative, borrowers still tend to increase their cutting, but the behaviour of lenders depends on the relative magnitudes of risks associated with interest rate and timber price, which is indicated by variances and covariance. Finnish data are used to evaluate the size of various risks and the sign of covariance. The evidence suggests that a statistically insignificant negative correlation exists and that the covariance is zero.

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.

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