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Aida Z. Kebede Baldev S. Dhillon Wolfgang Schipprack Jose L. Araus Marianne Bänziger Kassa Semagn Gregorio Alvarado Albrecht E. Melchinger 《Euphytica》2011,180(2):219-226
For in vivo production of doubled haploid (DH) lines in maize, the rate of haploid induction is of crucial importance. Maternal
haploid induction depends primarily on the inducer used as a pollinator. However, the source germplasm used as a maternal
parent and the environmental conditions for induction may also influence haploid induction and these aspects have not been
examined in tropical maize so far. The objectives of our study were to (i) monitor the variation for haploid induction rate
(HIR) among diverse source germplasm in tropical maize, (ii) determine the relative importance of general (GCA) and specific
(SCA) combining abilities for HIR, and (iii) investigate the influence of summer and winter seasons and genotype × season
interactions on this trait. Ten inbreds were mated in a half diallel design. The resulting 45 F1 single crosses were pollinated with the haploid inducer hybrid RWS × UH400 during the summer 2008 and winter 2009 seasons
in a lowland tropical environment in Mexico. HIR of the single crosses averaged over seasons ranged from 2.90 to 9.66% with
an overall mean of 6.74%. Mean HIR was significantly (P < 0.01) higher during the winter (7.37%) than summer season (6.11%). Significant (P < 0.01) variation was observed due to GCA effects of parental inbreds of single crosses but not for SCA, GCA × season and
SCA × season interactions. Our study underpins that a higher HIR in tropical maize can be obtained by selecting appropriate
source germplasm and undertaking pollination under favorable environmental conditions. 相似文献
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Asrat Asfaw Gebremedhen Woldegiorgis Semagn A. Kolech Gedif Mulugeta Dinka Mulugeta Abigail Ngugi 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2018,68(7):596-607
Micronutrient deficiencies in diets, including iron (Fe) and zinc (Zn), are an important public health problem across population in Ethiopia. Potato is a modest source of dietary nutrients. The purpose of this study was to assess the mineral (Fe & Zn) composition of potato germplasm in Ethiopia and grower's willingness to try new potato types. The Fe and Zn contents were assessed in peeled tubers of popular farmer varieties, and newly introduced Andean diploid group Phureja accessions and improved tetraploid clones grown in multi-location trials. Grower's preferences for the new potato types was assessed using a participatory approach. Significant variations in mineral and tuber yield traits exist among the germplasm assessed and broad-sense heritability appears to be high for most traits measured, suggesting that progress through breeding can be made among these materials. However, the slightly negative correlation of tuber yield with Fe and Zn content and user appreciation traits found in this study suggests that progress in improving crops for yield and enhanced Fe and Zn concentrations with end-user acceptable quality will be challenging. The results from this study provide baseline information on Fe and Zn composition of many popular farmer varieties in Ethiopia and end-user preference criteria for evaluating new potato varieties that would help to orient the biofortification breeding to the conditions and preference of farmers. 相似文献
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Evans Mutegi Fabrice Sagnard Moses Muraya Ben Kanyenji Bernard Rono Caroline Mwongera Charles Marangu Joseph Kamau Heiko Parzies Santie de Villiers Kassa Semagn Pierre Sibiry Traoré Maryke Labuschagne 《Genetic Resources and Crop Evolution》2010,57(2):243-253
The potential gene flow between a crop and its wild relatives is largely determined by the overlaps in their ecological and geographical distributions. Ecogeographical databases are therefore indispensable tools for the sustainable management of genetic resources. In order to expand our knowledge of Sorghum bicolor distribution in Kenya, we conducted in situ collections of wild, weedy and cultivated sorghum. Qualitative and quantitative morphological traits were measured for each sampled wild sorghum plant. Farmers’ knowledge relating to the management of sorghum varieties and autecology of wild sorghum was also obtained. Cluster analysis supports the existence of several wild sorghum morphotypes that might correspond to at least three of the five ecotypes recognized in Africa. Intermediate forms between wild and cultivated sorghum belonging to the S. bicolor ssp. drummondii are frequently found in predominantly sorghum growing areas. Crop-wild gene flow in sorghum is likely to occur in many agroecosystems of Kenya. 相似文献
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J. K. Mwololo S. N. Mugo T. Tefera P. Okori S. W. Munyiri K. Semagn M. Otim Y. Beyene 《Journal of pest science》2012,85(2):267-275
Post-harvest losses caused by the larger grain borer (LGB, Prostephanus truncatus) aggravate food insecurity among small-scale farmers. Host plant resistance is a method of LGB control which should be prioritized
in order to reduce these losses. The objective of this study was to assess maize resistance to the larger grain borer and
recognize some potential causes of resistance. One hundred and sixty-three (163) genotypes were tested; these included 85
hybrids, 2 checks, 6 open pollinate varieties, and 70 landraces, among them gene bank accessions. Grain biochemical content,
(protein, oil and starch) and insect resistance parameters, (percentage grain damage, weight loss, flour weight, and number
of emerged insects) were measured. There were significant differences (P < 0.001) among the genotypes for all the traits measured except number of insects. The most resistant hybrids were CKPH08024,
CKPH08009, CKPH08012, CKPH08014, CKP08033, CKPH08026, CKPH08014, and CKPH08003. The most resistant landrace accessions were
BRAZ 2451, GUAT 1162, BRAZ 2100, and GUAN 36. The percentage weight loss was found to be the most important resistance trait
for discriminating among genotypes for it had the largest canonical coefficient. Protein content had higher contribution to
variation in resistance to the larger grain borer and this probably contributed to the grain hardness which is a putative
trait of resistance to storage pests. The LGB-resistant germplasm could be used for the development of an integrated pest-management
program against the LGB. 相似文献
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