| 000 | 03529nab a22004577a 4500 | ||
|---|---|---|---|
| 999 |
_c59112 _d59104 |
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| 001 | 59112 | ||
| 003 | MX-TxCIM | ||
| 005 | 20231018192729.0 | ||
| 008 | 180129s2017 w |||p| p||| 00| 0 eng d | ||
| 024 | 8 | _ahttps://doi.org/10.2135/cropsci2016.09.0754 | |
| 040 | _aMX-TxCIM | ||
| 041 | _aeng | ||
| 100 | 1 |
_93375 _aMasuka, B. |
|
| 245 | 1 | 0 |
_aGenetic diversity among selected elite CIMMYT maize hybrids in East and Southern Africa _h[Electronic Resource] |
| 260 |
_aMadison, WI : _bCrop Science Society of America, _c2017. |
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| 500 | _aPeer review | ||
| 500 | _aOpen Access | ||
| 520 | _aGenetic gain within the CIMMYT Eastern and Southern Africa (ESA) hybrid maize (Zea mays L.) breeding program from 2000 to 2010 was recently estimated at 0.85 to 2.2% yr−1 under various environmental conditions. Over 100 varieties were disseminated from CIMMYT to farmers in ESA, hence the need to check genetic diversity and frequency of use of parents to avoid potential narrowing down of the genetic base. Fifty-five parents from CIMMYT ESA used in the hybrids were fingerprinted using genotyping-by-sequencing. Data analysis in TASSEL and MEGA6 generated pairwise genetic distances between parents of 0.004 to 0.4005. Unweighted pair group method with arithmetic mean (UPGMA) analysis produced two clusters (I and II) with two subclusters each (A and B) and two sub-subclusters (IAi and IAii). Principal coordinate analysis produced three clusters where IAi and IIA from the UPGMA analysis formed independent clusters while IAii, IB, and IIB clustered together. Lines were separated by pedigree and origin. Ninety-five percent frequency of pairwise genetic distances ranged between 0.2001 and 0.4000. However, only four of the 55 parents (CML444, CML395, CML312, and CML442) were each used in 15 to 30 of the 52 hybrids evaluated in the genetic gain study. The remaining 51 were used in one to four hybrids. Frequent use of the four parents gave 29 to 58% of the hybrids a narrow genetic base, posing risk in case of pest or disease outbreaks. Parents evaluated do not represent the genetic base of CIMMYT ESA but parents of the best-performing hybrids selected from 2000 to 2010. Breeders should ensure a wide genetic base for released varieties to avoid breakdown in case of pest or disease outbreaks. | ||
| 546 | _aText in English | ||
| 650 | 7 |
_aMaize _gAGROVOC _2 _91173 |
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| 650 | 7 |
_aGermplasm _gAGROVOC _2 _91136 |
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| 650 | 7 |
_aGenetic variation _gAGROVOC _2 _91129 |
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| 651 | 7 |
_94387 _aEast Africa _2AGROVOC |
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| 651 | 7 |
_95594 _aSouth Africa _2AGROVOC |
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| 700 | 1 |
_96191 _aBiljon, A. |
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| 700 | 1 |
_9879 _aCairns, J.E. _gGlobal Maize Program _8INT2948 |
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| 700 | 1 |
_aDas, B. _gGlobal Maize Program _gExcellence in Breeding _8INT2825 _9863 |
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| 700 | 1 |
_92259 _aLabuschagne, M. |
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| 700 | 1 |
_aMacRobert, J.F. _8INT2704 _gExcellence in Breeding _9583 |
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| 700 | 1 |
_9858 _aMakumbi, D. _gGlobal Maize Program _8INT2765 |
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| 700 | 1 |
_aMagorokosho, C. _gFormerly Global Maize Program _8INT2714 _9854 |
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| 700 | 1 |
_9779 _aZaman-Allah, M. _gGlobal Maize Program _8I1705364 |
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| 700 | 1 |
_92258 _aOgugo, V. |
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| 700 | 1 |
_9923 _aOlsen, M. _gGlobal Maize Program _8INT3333 |
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| 700 | 1 |
_aPrasanna, B.M. _gGlobal Maize Program _8INT3057 _9887 |
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| 700 | 1 |
_9876 _aAmsal Tesfaye Tarekegne _8INT2937 _gGlobal Maize Program |
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| 700 | 1 |
_9869 _aFentaye Kassa Semagn _8INT2869 _gGlobal Maize Program |
|
| 773 | 0 |
_gv. 57 no. 5, p. 2395-2404 _tCrop Science _wu444244 |
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| 856 | 4 |
_yOpen Access through DSpace _uhttps://hdl.handle.net/10883/19200 |
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| 942 |
_2ddc _cJA _n0 |
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