Selection of Elite dura-Type Parents to Produce Dwarf Progenies of Elaeis guineensis Using Genetic Parameters

The low annual growth rate of the stipe in oil palm progenies is desirable to increase these crops’ productive and economic life. Recurrent reciprocal selection (R.R.S.) has allowed the development of oil palm populations through several breeding cycles with an increased frequency of favorable alleles associated with traits of interest. The present study evaluated families derived from Deli dura × African dura crosses. For 12 years, the yield, vegetative characteristics, and the amount of oil in seven dura progenies were assessed to estimate, from the information collected, the genetic parameters, heritability, and phenotypic correlations among quantitative genetic traits of high-yielding dwarf progenies. The analysis was carried out using analysis of variance, followed by a comparison of means for all estimated traits. The effect of the progenies was highly significant (p ≤ 0.01) for most traits. The yield values, expressed in fresh fruit bunches (FFB) for the progenies, ranged from 165 to 208 kg per palm per year. The oil-to-bunch ratio (O/B) ranged from 17% to 19%, with an overall average of 18%. One of the essential characteristics in this study was the vertical growth of the stipe. Progenies P6 and P7 were identified as those with the lowest annual increase in height, with values of 0.29 and 0.33 m year−1. The values indicate that these are slow-growing cultivars with a high FFB yield and O/B. The highest heritabilities were found for the vegetative trait height (71.62%) and the number of leaflets (46.64%). The development of dura parents with slow growth characteristics in combination with a high bunch and oil production allows extending the productive life of the crop to more than 35 years, providing added value to obtaining differentiated cultivars of oil palm.

John Marion Thoday. 30 August 1916—25 August 2008

Professor John M. Thoday, ScD, FRS, was Arthur Balfour Professor of Genetics at the University of Cambridge from 1959 until 1983. In that position, he was influential in establishing genetics as an integral part of the undergraduate programme in biology at Cambridge, and he developed an active research programme that explored genetic processes underlying quantitative genetic traits, natural selection in sympatric populations and genetic variation in human and other populations. In more than 125 publications, he brought insightful attention to questions that had often been overlooked by others. Some of his most significant work explored the genetic basis of quantitative traits and thus pioneered approaches to understanding the mechanisms behind responses to selection. This helped set the stage to uncovering genes in the multiple-gene systems that determine polygenic characters in fields from medicine to agriculture. Other key work focused on disruptive, or diversifying, selection as a potential mechanism for populations to respond to adaptive challenges in nature. When his study of disruptive selection began, many in the field believed it was not even a possible process. In his many roles, John Thoday was a mentor who stimulated an open, respectful and intellectually rich academic environment for the Department of Genetics at Cambridge and for his field of creative activity.

Some quantitative genetic traits in Vietnamese indigenous Noi chicken from 0 to 28 days old

The aim of this study is to characterize some quantitative traits of Noi chicken, one of the Vietnamese famous native breeds for meat quality and fighting, at the stage of 0-28 days old. Therefore, 742 chicks were used to measure, record, analyze and evaluate on these traits. As results, there was significant difference in observation traits among stages of age (P=0.000). Interesting, the wings (+64.88%) and keel lengths (+58.83%) rapidly developed within the first week of life, followed by the most of other dimensions, especially breast diameter (+31.85%), thigh diameter (+71.17%) in the second week of age. An increase in the size of the measurements was due to development of the skeleton at observing time points along the experiment. However, there was strong development of muscle tissue in the second week of life as rate of the breast and thigh diameter was greatest. Noi chicks consumed amount of feed of 16.54 g/bird/day and gained a weight of 6.98 g/bird/day. Thus, their feed conversion ratio was 2.37 at the stage of 0-28 days old. Perhaps a direct positive relationship between observed traits and age were randomly established according biological characteristics of animal. This work provided initial benchmarks of Noi chicks for further studies.

Genetic Analyses of Endoreduplication in Zea mays Endosperm: Evidence of Sporophytic and Zygotic Maternal Control

Flow cytometry was used to assess the variability of endoreduplication in endosperms of maize inbred lines. Little variation was found between midwestern dent types, and high levels of endoreduplication were observed in popcorns. Endoreduplication is different between inbred lines by 13–18 days after pollination, and flow cytometric analysis of ploidy level was feasible until 20 DAP. To study the genetic regulation of endoreduplication, four inbreds were crossed to B73 and developing endosperms from both parental, reciprocal F1, and backcross generations were subjected to flow cytometric analysis. Three measurements of endoreduplication were calculated from these data and analyzed as quantitative genetic traits. Multiple models of trait inheritance were considered including triploid, diploid, sporophytic maternal, and maternal and paternal zygotic nuclear inheritance. Maternal zygotic effects, often considered a form of parental imprinting, and maternal sporophytic effects were detected. To test the feasibility of introgressing a high endoreduplication phenotype into a midwestern dent inbred line, a backcross population was generated from B73 × Sg18. Parental and progeny endoreduplication levels were compared and heritabilities assessed. The heritabilities calculated from these data generally agree with the values calculated in the larger crossing experiments.