Genetic divergence among slash pine second generation progenies at an early age

AbstractThe study was conducted to estimate the stability, adaptability, productivity and genetic parameters in Slash pine second-generation half-sib families, considering phenotypic traits in early age. Forty-four families from a first generation seed orchard in Colombo-PR, Brazil, were used in this study. Two progenies tests were established in a randomized complete block design. The first test was implemented in March 2009 in Ribeirão Branco, São Paulo state, containing 40 blocks, one tree per plot, 44 treatments (progenies) and 6 controls. Another test was implemented in Ponta Grossa, Paraná state, using the same experimental design and number of plants per plot, and with 24 treatments, 32 blocks. The growth traits evaluated were total height, diameter at breast height (dbh) and wood volume, within five years. The form traits evaluated were stem form, branch thickness, branch angle, number of branches, fork and fox tail five years after planting. Deviance analysis and estimates of stability, adaptability, productivity and genetic parameters were performed using the methods of best linear unbiased predictor (BLUP) and residual maximum likelihood (REML). There was significant variation among progenies for growth and form traits. Considerable genetic variation was detected mainly for wood volume. High coefficients of genetic variation and heritability showed low environmental influence on phenotypic variation, which is important for the prediction of genetic gain by selection. Crosses between different progenies individuals groups will be prioritized for obtaining heterotics genotypes and increase the probability of obtaining high specific combining ability.

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Short-term Progeny Tests and Second Generation Breeding in Slash Pine

Canadian Journal of Forest Research ◽

10.1139/x73-024 ◽

1973 ◽

Vol 3 (2) ◽

pp. 165-169

Author(s):

E. C. Franklin ◽

A. E. Squillace

Keyword(s):

First Generation ◽

Second Generation ◽

Slash Pine ◽

Mass Selection ◽

Progeny Testing ◽

Family Selection ◽

Short Term ◽

Major Disadvantage ◽

Selection For ◽

Almost All

Progeny testing is the most widely used method for intensive genetic evaluation of selected forest trees, but its major disadvantage is the length of time needed to get results. To circumvent this problem in selection for a multiproduct strain of slash pine (Pinuselliottii Engelm.), a system for short-term (3-year) progeny testing was developed. Oleoresin yields of selected second-generation 19-year-old parent trees were compared with yields of their 3-year-old offspring. Both parents and offspring showed little variation and a low offspring–parent correlation (r = 0.18), but other traits based on the same parent trees when they were 25 years old and their 3-year-old offspring showed relatively large amounts of variation and moderate to strong offspring-parent correlations: height, r =.56; volume, r = 0.43; turpentine, r = 0.71; ethanol–benzene extractives, r = 0.38; specific gravity, r = 0.43; moisture content, r = 0.34. Thus, indications are that additional gains could be made in the first generation by selecting among parent trees on a progeny performance basis in all traits except oleoresin yield. Original mass selection for oleoresin yield achieved gains of 100% improvement and apparently exploited almost all of the genetic variation in the base population. In second generation selection, progeny testing will be used primarily in screening for fusiform rust resistance. Between-family plus within-family selection will be used for other traits.

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Risk of schizophrenia in relation to parental origin and genome-wide divergence

Psychological Medicine ◽

10.1017/s0033291711002376 ◽

2011 ◽

Vol 42 (7) ◽

pp. 1515-1521 ◽

Cited By ~ 8

Author(s):

C. B. Pedersen ◽

D. Demontis ◽

M. S. Pedersen ◽

E. Agerbo ◽

P. B. Mortensen ◽

...

Keyword(s):

Genetic Divergence ◽

Second Generation ◽

Foreign Country ◽

Parental Origin ◽

Country Of Birth ◽

Foreign Born ◽

Registration System ◽

Second Generation Immigrants ◽

Genome Wide ◽

Increased Risk

BackgroundSecond-generation immigrants have an increased risk of schizophrenia, a finding that still lacks a satisfactory explanation. Various operational definitions of second-generation immigrants have been used, including foreign parental country of birth. However, with increasing global migration, it is not clear that parental country of birth necessarily is informative with regard to ethnicity. We compare two independently collected measures of parental foreign ethnicity, parental foreign country of birth versus genetic divergence, based on genome-wide genotypic data, to access which measure most efficiently captures the increased risk of schizophrenia among second-generation immigrants residing in Denmark.MethodA case–control study covering all children born in Denmark since 1981 included 892 cases of schizophrenia and 883 matched controls. Genetic divergence was assessed using principal component analyses of the genotypic data. Independently, parental foreign country of birth was assessed using information recorded prospectively in the Danish Civil Registration System. We compared incidence rate ratios of schizophrenia associated with these two independently collected measures of parental foreign ethnicity.ResultsPeople with foreign-born parents had a significantly increased risk of schizophrenia [relative risk (RR) 1.94 (95% confidence intervals (CI) 1.41–2.65)]. Genetically divergent persons also had a significant increased risk [RR 2.43 (95% CI 1.55–3.82)]. Mutual adjustment of parental foreign country of birth and genetic divergence showed no difference between these measures with regard to their potential impact on the results.ConclusionsIn terms of RR of schizophrenia, genetic divergence and parental foreign country of birth are interchangeable entities, and both entities have validity with regard to identifying second-generation immigrants.

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A Community Based High Risk Register for Hearing Loss

Journal of Speech and Hearing Disorders ◽

10.1044/jshd.4704.373 ◽

1982 ◽

Vol 47 (4) ◽

pp. 373-375 ◽

Cited By ~ 2

Author(s):

James L. Fitch ◽

Thomas F. Williams ◽

Josephine E. Etienne

Keyword(s):

Hearing Loss ◽

System Identification ◽

High Risk ◽

Language Learning ◽

Education Program ◽

Communication System ◽

Auditory Signal ◽

Early Age ◽

Community Based ◽

Children With Hearing Loss

The critical need to identify children with hearing loss and provide treatment at the earliest possible age has become increasingly apparent in recent years (Northern & Downs, 1978). Reduction of the auditory signal during the critical language-learning period can severely limit the child's potential for developing a complete, effective communication system. Identification and treatment of children having handicapping conditions at an early age has gained impetus through the Handicapped Children's Early Education Program (HCEEP) projects funded by the Bureau of Education for the Handicapped (BEH).

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