Download or read book Response to Thirteen Cycles of Reciprocal Full Sib Recurrent Selection in the BS10 and BS11 Maize Zea Mays L Populations written by Benjamin Aaron Ford and published by . This book was released on 2001 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increases in grain yield, the primary trait for selection, include a direct response of 2.2 percent per cycle in the population cross, and indirect responses of 3.3 and 1.2 percent per cycle in BS10 and BS11, respectively, but only the response for BS11 fits a linear model. Linear trends through the first nine selection cycles, however, indicate a 4.6 percent per cycle increase for the population cross, as well as increases of 1.6 percent in BS10 and 1.6 percent in BS11 parent populations. Evaluations of random S1 line performance for BS10CO, BS10C13, BS11CO, and BS11C13 indicate decreasing trends in genetic variability over 13 cycles of FR. Exceptions are grain yield in BS10 and BS11 and plant height in BS11. While genetic variance estimates for grain yield are nearly equal for BS11CO and BS11C13, a nearly significant increase in variability is evident from BS10CO to BS10C13. Variability estimates suggest FR for grain yield in BS10 and BS11 will be effective in future selection cycles.
Download or read book Response to Eight Cycles of Full sib Reciprocal Recurrent Selection for Grain Yield and Standability in BS10 and BS11 Maize Populations written by Guillermo Hugo Eyherabide and published by . This book was released on 1989 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Proceedings of the Iowa Academy of Science written by Iowa Academy of Science and published by . This book was released on 1981 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: List of members in each volume.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2002 with total page 972 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plant Breeding Abstracts written by and published by . This book was released on 1999 with total page 1664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Tolerance to High Plant Densities and Plant Efficiency of Maize Breeding Population Developed by Recurrent Selection of Grain Yield written by T.M. Crosbie and published by . This book was released on 1978 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several recurrent relection schemes are being used to improve grain-yield performance of several maize (Zea mays L.) populations at the Iowa Agriculture and Home Economics Experiment Station. Three cycles of reciprocal full-sib selection in Iowa Two-ear Synthetic [BS10(FR)] and Pioneer Twc-ear Composite [BS11(FR)], seven cycels of reciprocal recurrent selection in Iowa Stiff Stalk Synthetic [BSSS(R)], Iowa Corn Borer Synthetic #1 [BSCB1(R)], and five cycels of half-sib recurrent selection in Lancaster Surecrop 9LANC) with maize inbred, Hy, as tester have been completed. I grew testcrosses of unimproved and improved populations of BS10(FR), BS11(FR), BSSS(R), BSCB1(R) And LANC, plus population crosses (i.e., CO X CO, CN X CN) of BS10(FR) X BS11(FR) and BSSS(R) X BSCB1(R) at three plant densities in three environments. Testers were maize inbreds Mo17, B77, and B79, My research was conducted: (1) to evaluate respones to plant densities of the CO and CN populations, (2) to study changes in several morphological and physiological traits associated with recurrent selection for increased grain yield, and (3) to caompare results obtained for testcrosses and populations crosses to evaluate combining ability for grain yield, density tolerance, and physiological traits. Reciprocal full-sib selection did not improve the response to plant densities of testcrosses and population crosses of BS10(FR) and BS11(FR). Furthermore, selection did not increase grain yield of BS10(FR) X BS11(FR) at 39.5 and 79.0 M plants/ha or of (...).
Download or read book American Doctoral Dissertations written by and published by . This book was released on 2001 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct and Correlated Response to Recurrent Selection for Grain Yield in Maize Breeding Populations written by M.A.B. Fakorede and published by . This book was released on 1977 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dr. G. F. Sprague initiated recurrent selection programs during the 1940' and 1950' to improve the grain-yield performance of several maize (Zea mays L.) population at the Iowa Agriculture and Home Economics Experiments Station. Seven cycles of reciprocal recurrent selections (RRS) in Iowa Stiff Stalk Synthetic (BSSS) and Iowa Corn Borer Synthetic #1 (BSCB1), and six cycles of recurrent half-sib selection (HS) in the open-pollinated variety 'Alph'(i.e., BS12) have been completed. Inbred B14 was the tester in the HS program. My objectives were to (1) evaluate progress that resulted from the RRS and HS programs and (2) evaluate changes in several other traits associated with recurrent selection for grain yield. I evaluated the CO x CO, C5, and C7 x C7 of the RRS program, and CO and C6 of the HS program, each testcrossed to B14A. Estimated gain from seven cycles of RRS was 2.06 q/ha (or 5.21%) per cycle and observed difference in mean yield between CO and C6 of the program was 2.25 q/ha (or 6.00%) per cycle. Improved hybrids outyield their unimproved counterparts at all levels of nitrogen (0, 90, 180, and 270 kg N/ha) and plant density (39,000; 59,300; 79,000; and 98,800 plants/ha) investigated. Each hybrid displayed a positive, curvilinear response to nitrogen and a negative, linear response to plant density. Stability and adaptation-reaction analysis revealed that improved hybrids consistently demonstrated greater adaptation to high-nitrogen environments, but their unimproved counterparts did not take (...).
Download or read book Commencement written by Iowa State University and published by . This book was released on 2001 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agrindex written by and published by . This book was released on 1992 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Quantitative Trait Response Evaluation to Selection in the BS13 S Maize Zea Mays L Population written by Clinton J. Turnbull and published by . This book was released on 2006 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seven cycles of half-sib recurrent selection were conducted in the BSSS maize population followed by ten cycles of S2 progeny recurrent selection. The population under S2 progeny recurrent selection is formally known as BS13(S). The selection criteria have always placed importance on high grain yield, low grain moisture, and reduced plant lodging. Two evaluations estimating the response of multiple agronomic traits in multiple response units including the population sampled at F[subscript IS] = 0, F[subscript IS] = 0.5, and F[subscript IS] = 0.75 levels of inbreeding, and multiple testcrosses of the population were conducted. The average response of grain yield in the F[subscript IS] = 0.5 and F[subscript IS] = 0.75 response units (i.e. inbred response units) of the population are significantly greater than the average responses in both the panmictic population and multiple testcrosses of panmictic population. There is no statistical grain yield response to selection in the F[subscript IS] = 0 response unit (panmictic population). A testcross of the panmictic population to BS13(S)C0 has an average response greater than the panmictic population indicating that the limited response in the F[subscript IS] = 0 response unit is not likely due to random genetic drift, however, the allelic frequencies are diverging from the progenitor population. Favorable responses have been observed for root lodging in all of the response units however, a limited response for stalk lodging exist. The response of grain moisture is inconsistent between the two evaluations likely as a result of inconsistent selection practices and the difficulty to select for this trait. We hypothesize that the most important reason for the realized lack of response in the panmictic population is due to a low inbred-outbred correlation and may be caused by an overdominant-like gene action within this population. To avoid the necessity for assumptions about gene action controlling the traits in maize and importance of additive and non-additive effects, the genetic gain equation must be developed in relation to the selection unit and target response unit (i.e. S1s, S2S, half-sibs, or full-sibs). This dissertation supports both the genetic gain equations reported by Wardyn (2006) and the hypothesis of overdominant-like gene action in this population reported by Edwards and Lamkey (2002).
Download or read book Response to Full sib Reciprocal Recurrent Selection in a Double cross Maize Population written by Eduardo J. Graterol M. and published by . This book was released on 2005 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Genetic Variability Using Full sib Families Within and Between the BS10 and BS11 Synthetic Maize Zea Mays L Populations for the Original and Tenth Cycle of Selection written by Todd Eugene Frank and published by . This book was released on 1997 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of 11 Cycles of Reciprocal Recurrent Selection in BSSS and BSCB1 Maize Populations written by Vichien Keeratinijakal and published by . This book was released on 1990 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Correlated Responses to Recurrent Selection for Grain Yield in Maize written by M. A. B. Fakorede and published by . This book was released on 1982 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments were conducted in there field environments with the following objectives: (1) to evaluate the progress from seven cycles of reciprocal recurrent selection in Iowa Stiff Stalk Synthetic (BSSS(R) and Iowa Corn Borer Synthetic #1 (BSCB(R) and six cycles of half-sib family selection in 'Alph' (i.e. BS12) maize (Zea mays L.) populations, (2) to compare the response of unimproved and improved maize variety hybrids to different levels of nitrogen fertilizer and plant density, and (3) to evaluate the influence of nitrogen and plant density on the morphological and physiological traits associated with recurrent selection for grain yield in maize. Each experiment was grown in randomized complete blocks with a split-split-plot arrangement and two replications. Nitrogen fertilizer levels (0,90,180, and 270 kg N/ha) were main plots, plant densities (39,500; 59,300; 79,000; and 98,800 plants/ha) were subplots, and five variety hybrids, BSSS(R)CO x BSCB1(R)CO, BSSS(R)C5 x BSCB1(R)C5, BSSS(R)C7 x BSCB1(C7, BS12C0 x B14A, and BS12C6 x B14A, were randomized as sub-subplots. We obtained data on grain yield and grain-yield components, flowering traits, plant traits, leaf area, leaf orientation, lodging, dry-matter productivity, and harvest index.(...).
Download or read book Observed Response and Genetic Variability in Two Maize Populations After Four Cycles of Reciprocal Full sib Selection written by Manuel Montecer Lantin and published by . This book was released on 1980 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book One Vs Two Genetic Pools for Full sib Reciprocal Recurrent Selection in Maize Zea Mays L written by José Luis De León and published by . This book was released on 1979 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
