A testcross procedure for selecting exotic strains to improve pure-line cultivars in predominantly self-fertilizing species

Methods for identifying germplasm carrying alleles with the potential to improve a particular single-cross hybrid have been proposed and discussed in recent years. There is a need for similar methods to be used in breeding crops for which pure-line cultivars, rather than hybrids, are the goal. The objective of this research was to develop a method to identify germplasm lines with the potential to contribute favorable alleles not present in a specified pure line or set of pure lines. Given a set of adapted pure lines (A ₁, A ₂ ..., A _m) to be improved and a set of germplasm lines (P ₁ P ₂ ..., P _f), the procedure consists of producing all f x m possible hybrids and evaluating them along with the parents. The testcross statistic T _ij is defined by T _ij=(F _ij–A _j)+(1–) (F _ij–P _i), where A _j, P _i, and F _ij represent the performance of thej ^th adapted line, the i ^th germplasm line, and their hybrid, respectively. The statistic is the mean value of T _ij over all adapted parents A _j. If =(1/2)(1+d), where d = the mean degree of dominance, then T _ij measures the potential for alleles from P _i to improve A _j and measures the potential for alleles from P _i to improve the set A ₁, A ₂ ..., A _m. Use of data on soybean and peanut hybrids published by other researchers suggests that the value assumed for d has little effect on the P _i chosen. The ability of the T _ij and statistics to identify germplasm strains carrying rare favorable alleles should be assessed in empirical studies.Joint contribution: OARDC (Journal Articale No. 161-94), USDAARS, Iowa Agriculture and Home Economics Expriment Station (Journal Paper No. J-16109; Project 2985), and Agreculture and Agri-Food Canada. Salaries and research support for S. K. St. Martin Provided by state and federal funds appropriated to the Ohio Agricultural Research and Development Center, Ohio State University     

大豆籽粒蓝脐性状及其分离规律

控制大豆白花亲本籽粒脐色的基因有带Ｒ与ｒ之分,带Ｒ基因的白花产本与紫花亲本杂交,Ｆ１代籽料出现蓝脐性状,其基因型为Ｉ－Ｒ－Ｗ１－ｔｔ。当控制脐色的基因有两对相差时（Ｒ、ｒ;Ｗ１、ｗ１）Ｆ２代籽粒脐色分离蓝脐与无色脐之比为９∶７。     

Cancer Risks in Parents Who had a Child with a Congenital Malformation

Cancer risk in parents may be related to congenital malformations (CMs) in their children if they share genetic susceptibility or environmental exposure that may be teratogenic and carcinogenic. We conducted a population‐based cohort study based on Danish register data. We identified 795,607 mothers and 781,424 fathers who had all their children between 1977 and 2007 in Denmark. Information on CM was obtained from the Danish Hospital Registry and information on cancer was obtained from the Danish Cancer Registry. Parents were followed from the birth of their first child until the diagnosis of cancer, death, emigration, or December 31, 2007. We used Cox regression models to estimate hazard ratios (HRs) for cancer including cancer in specific organs in mothers and fathers. Overall, 75,701 (9.5%) mothers and 72,724 (9.3%) fathers had at least one child diagnosed with CMs within the first year of life. Neither mothers (HR = 1.04; 95% CI: 0.99–1.04) nor fathers (HR = 1.03; 95% CI: 0.98–1.09) who had a child with a CM had a higher overall risk of cancer. Mothers (HR = 0.76, 95% CI: 0.58–1.00) or fathers (HR = 0.89, 95% CI: 0.66–1.19) who had a child with a chromosomal malformation had a lower overall cancer risk. The findings also showed a higher risk for some specific types of cancer in parents who had children with a CM in the specific system. Some, or perhaps all, of these findings may be due to chance caused by multiple comparisons. We present all results on paper or online to provide clues for further research and to avoid publication bias.     

上海市患儿家长健康教育需求及现状调查

??????? 目的 了解上海市患儿家长对健康教育知识和方式的需求情况,提出做好患儿家长健康教育的方法和途径。方法 在文献检索和专家咨询的基础上,采用自行设计的调查问卷对200名门诊患儿家长和300名住院患儿家长进行调查,并对调查结果进行统计分析。结果 患儿家长对健康教育知识的需求广泛,教育方式的需求多样,对目前开展的健康教育,住院患儿家长的满意度要好于门诊患儿家长,但仍存在一定的不足。 结论 通过满足患儿家长对健康知识的需求、丰富健康教育的形式、加强医护人员人文教育等途径来做好患儿家长的健康教育。     

Controlled study of critical parent and family factors in the obesigenic environment

Objective: Critical gaps remain in our understanding of the obesigenic family environment. This study examines parent and family characteristics among obese youth presenting for treatment in a clinic setting. Research Methods and Procedures: Families of 78 obese youth (BMI z‐score = 2.4; age, 8 to 16 years; 59% girls; 49% African‐American) were compared with 71 non‐overweight (BMI z‐score = ?0.02) demographically matched comparisons. Parents completed measures assessing family demographics, psychological distress (Symptom Checklist 90‐Revised), and family functioning both broadly (Family Environment Scale: Conflicted, Support, Control) and at mealtimes (About Your Child's Eating‐Revised: Mealtime Challenges, Positive Mealtime Interaction). Height and weight were obtained from all participants. Results: Compared with mothers and fathers of non‐overweight youth, parents of obese youth had significantly higher BMIs (p < 0.001). Mothers of obese youth reported significantly greater psychological distress (p < 0.01), higher family conflict (p < 0.05), and more mealtime challenges (p < 0.01). Less positive family mealtime interactions were reported by both mothers (p < 0.01) and fathers (p < 0.05) of obese youth. These group differences did not vary by child sex or race. Logistic regression analyses indicated that maternal distress and mealtime challenges discriminated between obese and non‐overweight youth after controlling for maternal BMI. Family conflict was explained, in part, by maternal distress. Discussion: Obese youth who present for treatment in a clinic setting are characterized by psychosocial factors at the parent and family level that differ from non‐overweight youth. These data are critical because they identify factors that may be serving as barriers to a family's or youth's ability to implement healthy lifestyle behaviors but that are potentially modifiable.     

Parent overweight predicts daughters' increase in BMI and disinhibited overeating from 5 to 13 years

Objective: To assess whether parental overweight status and disinhibited overeating are predictive of daughters’ accelerated weight gain and disinhibited overeating. Research Methods and Procedures: Participants were part of a longitudinal study of girls (N = 197) and their parents. Measured height and weight were used to calculate BMI [weight (kilograms)/height (meters)²]. Parents’ disinhibited eating behavior was assessed using the Eating Inventory. Girls’ disinhibited eating was assessed using a behavioral protocol to measure eating in the absence of hunger. Girls were classified based on parental overweight at study entry into four groups: neither, mother only, father only, or both parents overweight. Results: Girls with both parents overweight had the most rapid increases in BMI from 5 to 13 years of age; BMI increased most slowly among the neither parent overweight group, with intermediate increases in BMI among mother only and father only overweight groups. Daughters with both parents overweight at study entry were eight times more likely to be overweight at age 13, controlling for daughters’ weight at age 5. Girls with both parents overweight had higher levels of disinhibited eating across all ages than all other groups. Although girls in all parental weight status groups showed increases in disinhibited eating over time, girls with both parents overweight had larger increases in disinhibited eating over time compared with all other groups. Discussion: Girls growing up in families differing in parental overweight had divergent developmental trajectories for BMI and disinhibited overeating. Findings reveal the need to focus prevention efforts on overweight parents of young children.     

Bird predation by tawny owls (Strix aluco L.) and its effect on the reproductive performance of tits

The density of great tit Parus major L. and blue tit Parus caeruleus L. was artificially increased by placing nest-box colonies for these species in the vicinity of the nests of breeding tawny owls during 1993–1997. Bird prey composition in the owl nests, the proportion of parents disappearing from the breeding tit populations and the reproductive performance of the widowed parents were analysed. The frequency of predation on tits by tawny owls was greater in areas where tit density had been artificially increased. Owls preyed more on tits during the feeding period of owlets than during the incubation period and more in years when snow covered the ground during the incubation period than when it did not. Mortality due to predation was male biased and more females lost their mates in populations breeding near tawny owl nests. Reproductive performance of the widowed parents was lower and their body weights were lighter at the end of the nestling period than those found in birds rearing youngs with their mates. Predation by owls increased the between-year turnover in the breeding tit population: widowed parents did not return to the nesting site for the next breeding season.     

A monozygotic twin pair with β-thalassemia carrier status in a Dudh Kharia tribal family of Orissa

BACKGROUND:

The β-thalassemia syndrome is a genetically inherited commonly encountered hematological disorder in the state of Orissa. It causes high degree of morbidity, mortality and fetal wastage in the poor vulnerable people.

AIMS AND OBJECTIVES:

There is an equal probability (50% chance) in every singleton pregnancy that a carrier parent of β-thalassemia major would either bear normal or carrier offspring, but not two offspring with carrier of β-thalassemia major genotype together. For the first time, a carrier parent of β-thalassemia major gene has born progeny (three daughters and a twin male offspring) with a carrier status of β-thalassemia major in Dudh Kharia tribal family studied from Sundargarh district of Orissa.

MATERIALS AND METHODS:

We screened randomly selected population of Dudh Kharia tribe from Sundargarh district of Orissa for hemoglobinopathies to assess the extent of the problem, design possible interventions and provide genetic counseling to them. A family with twin children was identified during screening in Lata Gaon in Bargaon block of Sundargarh district of Orissa for the above-mentioned study. Background information for this family such as name, age, sex, tribe, native place, reproductive history, family pedigree and clinical signs and symptoms were also recorded. Standardized genetic and hematological procedures and techniques were followed for analysis.

RESULTS:

Laboratory investigations for alkaline electrophoresis of blood lysate on cellulose acetate membrane showed raised hemoglobin A₂ level in mother (Hb A₂ = 5.3%), in three daughters (Hb A₂ =6.5, 5.9, 5.5% in chronological and birth order), in two twin sons (Hb A₂ =5.9% and 6.0%) and normal (Hb A₂ = 3.3%) for father. Hence, all the children i.e., three daughters and two twin sons, including the mother were β-thalassemia carriers. Since all the hematological parameters i.e., red cell indices, G-6-PD enzyme activity, ABO and Rhesus blood groups and identical β-thalassemia (trait) genotypes with identical clinical manifestations and hematological profile of the twin sons under similar environmental conditions, hence they were labeled as identical monozygotic twins.

CONCLUSIONS:

It is a rare occasion when a single pregnancy carries either one or two abnormal genotypes at a time in a womb in human beings. Monozygotic twins are genetically alike and provide appraisal of the expression of identical genotype under the different environmental conditions.     

A definition of unknown parent groups based on bull usage patterns across herds

In genetic evaluations, the definition of unknown parent groups (UPG) is usually based on time periods, selection path and flows of foreign founders. The definition of UPG may be more complex for populations presenting genetic heterogeneity due to both, large national expansion and coexistence of artificial insemination (AI) and natural service (NS). A UPG definition method accounting for beef bull flows was proposed and applied to the French Charolais cattle population. It assumed that, at a given time period, unknown parents belonged to the same UPG when their progeny were bred in herds that used bulls with similar origins (birth region and reproduction way). Thus, the birth period, region and AI rate of a herd were pointed out to be the three criteria reflecting genetic disparities at the national level in a beef cattle population. To deal with regional genetic disparities, 14 regions were identified using a factorial approach combining principal component analysis and Ward clustering. The selection nucleus of the French cattle population was dispersed over three main breeding areas. Flows of NS bulls were mainly carried out within each breeding area. On the contrary, the use and the selection of AI bulls were based on a national pool of candidates. Within a time period, herds of different regions were clustered together when they used bulls coming from the same origin and with an estimated difference of genetic level lower than 20% of genetic standard deviation (σg) for calf muscle and skeleton scores (SS) at weaning. This led to the definition of 16 UPG of sires, which were validated as robust and relevant in a sire model, meaning numerically stable and corresponding to distinct genetic subpopulations. The UPG genetic levels were estimated for muscle and SS under sire and animal models. Whatever the trait, differences between bull UPG estimates within a time period could reach 0.5 σg across regions. For a given time period, bull UPG estimates for muscle and SS were generally larger by 0.30 to 0.75 σg than those of cows. Including genetic groups in the evaluation model increased the estimated genetic trends by 20% to 30%. It also provoked re-ranking in favor of bulls and cows without pedigree.     

The Heritability Theory of Heterosis and Its Meaning for Global Agriculture

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