Genetic diversity of potato for nitrogen use efficiency under low input conditions in Ethiopia

Baye Berihun Getahun

Research output: Thesisinternal PhD, WUAcademic

Abstract

Potato is a prime food security crop for smallholder farmers in the highland part of North western Ethiopia. In this region, nutrient availability, especially nitrogen (N) is a major constraint for crop productivity. To obtain insight in the possibility of improving potato for growth under low N input conditions in Ethiopia, we evaluated CxE diploid back cross population,  modern European and Ethiopian potato cultivars and local Ethiopian cultivars for their ability to grow and produce tubers under low and high N input conditions.  The experiments were conducted under rainfed and irrigation conditions. Eighty-eight Dutch cultivars and 9 Ethiopian cultivars were evaluated in three locations in North-western Ethiopia, in 2013 and in 2015. The two years represent two different growth seasons: rain-fed (June-October 2013) and irrigated cultivation (February-June 2015). Similarly 100 CxE diploid back cross potato genotypes were evaluated in both rainfed and irrigation production seasons in 2014. The  Growth of the plants was monitored throughout the growth cycle using canopy cover measurements, with modelled canopy characteristics, and other agronomic traits were measured as per the description. The effect of season and location was further investigated by a GGE Biplot genotype-by-environment interaction analysis, and genetic factors determining phenotypic traits and yield were  identified through QTL mapping and association mapping. Ethiopian cultivars showed a remarkable, environment-dependent difference in utilisation of the canopy for tuber production. While total photosynthetic capacity was higher in Ethiopian cultivars than in Dutch cultivars in rainfed production season at Injibara, tuber production was higher in Dutch cultivars. This low radiation use efficiency was not observed in the other rain-fed location (Debre-Tabor). A Genotype by Environment analysis using GGE biplots demonstrates that, Irrespective of the N levels and locations, rainfed production season test environments were grouped as one mega environment and irrigation production season test environments as the other mega environment, indicating most of the variation for yield and nitrogen use efficiency (NUE) in the dataset may be  caused by the effect of rain-fed vs irrigation season. Further trials are needed to confirm this result. The QTL mapping with the CxE diploid population and GWAS analysis with the Dutch cultivars discovered both season-environment and N-specific QTL as well as constitutive  QTLs. Overall, N availability affects Dutch and Ethiopian cultivars differentially, with strong environmental interaction on canopy and yield traits. Rainfed and irrigated seasons in Ethiopia may require different breeding programs for improved yield under varying fertilizer levels. Both constitutive and environment-specific QTLs were identified that may be targets for breeding prorgams towards improved yield under Ethiopian cultivation conditions.

Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
Supervisors/Advisors
  • Visser, Richard, Promotor
  • van der Linden, Gerard, Co-promotor
Award date18 Sep 2017
Place of PublicationWageningen
Publisher
Print ISBNs9789463436595
DOIs
Publication statusPublished - 2017

Fingerprint

nutrient use efficiency
Ethiopia
potatoes
genetic variation
cultivars
quantitative trait loci
irrigation
canopy
tubers
diploidy
rain
genotype
radiation use efficiency
breeding
crops
food security
agronomic traits
nutrient availability
chromosome mapping
highlands

Keywords

  • solanum tuberosum
  • potatoes
  • genetic diversity
  • nitrogen
  • plant breeding
  • ethiopia
  • nutrient use efficiency

Cite this

Getahun, Baye Berihun. / Genetic diversity of potato for nitrogen use efficiency under low input conditions in Ethiopia. Wageningen : Wageningen University, 2017. 219 p.
@phdthesis{e4c68d5f97cb46098a350f6d91c0b641,
title = "Genetic diversity of potato for nitrogen use efficiency under low input conditions in Ethiopia",
abstract = "Potato is a prime food security crop for smallholder farmers in the highland part of North western Ethiopia. In this region, nutrient availability, especially nitrogen (N) is a major constraint for crop productivity. To obtain insight in the possibility of improving potato for growth under low N input conditions in Ethiopia, we evaluated CxE diploid back cross population,  modern European and Ethiopian potato cultivars and local Ethiopian cultivars for their ability to grow and produce tubers under low and high N input conditions.  The experiments were conducted under rainfed and irrigation conditions. Eighty-eight Dutch cultivars and 9 Ethiopian cultivars were evaluated in three locations in North-western Ethiopia, in 2013 and in 2015. The two years represent two different growth seasons: rain-fed (June-October 2013) and irrigated cultivation (February-June 2015). Similarly 100 CxE diploid back cross potato genotypes were evaluated in both rainfed and irrigation production seasons in 2014. The  Growth of the plants was monitored throughout the growth cycle using canopy cover measurements, with modelled canopy characteristics, and other agronomic traits were measured as per the description. The effect of season and location was further investigated by a GGE Biplot genotype-by-environment interaction analysis, and genetic factors determining phenotypic traits and yield were  identified through QTL mapping and association mapping. Ethiopian cultivars showed a remarkable, environment-dependent difference in utilisation of the canopy for tuber production. While total photosynthetic capacity was higher in Ethiopian cultivars than in Dutch cultivars in rainfed production season at Injibara, tuber production was higher in Dutch cultivars. This low radiation use efficiency was not observed in the other rain-fed location (Debre-Tabor). A Genotype by Environment analysis using GGE biplots demonstrates that, Irrespective of the N levels and locations, rainfed production season test environments were grouped as one mega environment and irrigation production season test environments as the other mega environment, indicating most of the variation for yield and nitrogen use efficiency (NUE) in the dataset may be  caused by the effect of rain-fed vs irrigation season. Further trials are needed to confirm this result. The QTL mapping with the CxE diploid population and GWAS analysis with the Dutch cultivars discovered both season-environment and N-specific QTL as well as constitutive  QTLs. Overall, N availability affects Dutch and Ethiopian cultivars differentially, with strong environmental interaction on canopy and yield traits. Rainfed and irrigated seasons in Ethiopia may require different breeding programs for improved yield under varying fertilizer levels. Both constitutive and environment-specific QTLs were identified that may be targets for breeding prorgams towards improved yield under Ethiopian cultivation conditions.",
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doi = "10.18174/420903",
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Genetic diversity of potato for nitrogen use efficiency under low input conditions in Ethiopia. / Getahun, Baye Berihun.

Wageningen : Wageningen University, 2017. 219 p.

Research output: Thesisinternal PhD, WUAcademic

TY - THES

T1 - Genetic diversity of potato for nitrogen use efficiency under low input conditions in Ethiopia

AU - Getahun, Baye Berihun

N1 - WU thesis 6748 Includes bibliographical references. - With summaries in Dutch and English

PY - 2017

Y1 - 2017

N2 - Potato is a prime food security crop for smallholder farmers in the highland part of North western Ethiopia. In this region, nutrient availability, especially nitrogen (N) is a major constraint for crop productivity. To obtain insight in the possibility of improving potato for growth under low N input conditions in Ethiopia, we evaluated CxE diploid back cross population,  modern European and Ethiopian potato cultivars and local Ethiopian cultivars for their ability to grow and produce tubers under low and high N input conditions.  The experiments were conducted under rainfed and irrigation conditions. Eighty-eight Dutch cultivars and 9 Ethiopian cultivars were evaluated in three locations in North-western Ethiopia, in 2013 and in 2015. The two years represent two different growth seasons: rain-fed (June-October 2013) and irrigated cultivation (February-June 2015). Similarly 100 CxE diploid back cross potato genotypes were evaluated in both rainfed and irrigation production seasons in 2014. The  Growth of the plants was monitored throughout the growth cycle using canopy cover measurements, with modelled canopy characteristics, and other agronomic traits were measured as per the description. The effect of season and location was further investigated by a GGE Biplot genotype-by-environment interaction analysis, and genetic factors determining phenotypic traits and yield were  identified through QTL mapping and association mapping. Ethiopian cultivars showed a remarkable, environment-dependent difference in utilisation of the canopy for tuber production. While total photosynthetic capacity was higher in Ethiopian cultivars than in Dutch cultivars in rainfed production season at Injibara, tuber production was higher in Dutch cultivars. This low radiation use efficiency was not observed in the other rain-fed location (Debre-Tabor). A Genotype by Environment analysis using GGE biplots demonstrates that, Irrespective of the N levels and locations, rainfed production season test environments were grouped as one mega environment and irrigation production season test environments as the other mega environment, indicating most of the variation for yield and nitrogen use efficiency (NUE) in the dataset may be  caused by the effect of rain-fed vs irrigation season. Further trials are needed to confirm this result. The QTL mapping with the CxE diploid population and GWAS analysis with the Dutch cultivars discovered both season-environment and N-specific QTL as well as constitutive  QTLs. Overall, N availability affects Dutch and Ethiopian cultivars differentially, with strong environmental interaction on canopy and yield traits. Rainfed and irrigated seasons in Ethiopia may require different breeding programs for improved yield under varying fertilizer levels. Both constitutive and environment-specific QTLs were identified that may be targets for breeding prorgams towards improved yield under Ethiopian cultivation conditions.

AB - Potato is a prime food security crop for smallholder farmers in the highland part of North western Ethiopia. In this region, nutrient availability, especially nitrogen (N) is a major constraint for crop productivity. To obtain insight in the possibility of improving potato for growth under low N input conditions in Ethiopia, we evaluated CxE diploid back cross population,  modern European and Ethiopian potato cultivars and local Ethiopian cultivars for their ability to grow and produce tubers under low and high N input conditions.  The experiments were conducted under rainfed and irrigation conditions. Eighty-eight Dutch cultivars and 9 Ethiopian cultivars were evaluated in three locations in North-western Ethiopia, in 2013 and in 2015. The two years represent two different growth seasons: rain-fed (June-October 2013) and irrigated cultivation (February-June 2015). Similarly 100 CxE diploid back cross potato genotypes were evaluated in both rainfed and irrigation production seasons in 2014. The  Growth of the plants was monitored throughout the growth cycle using canopy cover measurements, with modelled canopy characteristics, and other agronomic traits were measured as per the description. The effect of season and location was further investigated by a GGE Biplot genotype-by-environment interaction analysis, and genetic factors determining phenotypic traits and yield were  identified through QTL mapping and association mapping. Ethiopian cultivars showed a remarkable, environment-dependent difference in utilisation of the canopy for tuber production. While total photosynthetic capacity was higher in Ethiopian cultivars than in Dutch cultivars in rainfed production season at Injibara, tuber production was higher in Dutch cultivars. This low radiation use efficiency was not observed in the other rain-fed location (Debre-Tabor). A Genotype by Environment analysis using GGE biplots demonstrates that, Irrespective of the N levels and locations, rainfed production season test environments were grouped as one mega environment and irrigation production season test environments as the other mega environment, indicating most of the variation for yield and nitrogen use efficiency (NUE) in the dataset may be  caused by the effect of rain-fed vs irrigation season. Further trials are needed to confirm this result. The QTL mapping with the CxE diploid population and GWAS analysis with the Dutch cultivars discovered both season-environment and N-specific QTL as well as constitutive  QTLs. Overall, N availability affects Dutch and Ethiopian cultivars differentially, with strong environmental interaction on canopy and yield traits. Rainfed and irrigated seasons in Ethiopia may require different breeding programs for improved yield under varying fertilizer levels. Both constitutive and environment-specific QTLs were identified that may be targets for breeding prorgams towards improved yield under Ethiopian cultivation conditions.

KW - solanum tuberosum

KW - potatoes

KW - genetic diversity

KW - nitrogen

KW - plant breeding

KW - ethiopia

KW - nutrient use efficiency

KW - solanum tuberosum

KW - aardappelen

KW - genetische diversiteit

KW - stikstof

KW - plantenveredeling

KW - ethiopië

KW - nutriëntengebruiksefficiëntie

U2 - 10.18174/420903

DO - 10.18174/420903

M3 - internal PhD, WU

SN - 9789463436595

PB - Wageningen University

CY - Wageningen

ER -