scholarly journals An assessment of wheat yield sensitivity and breeding gains in hot environments

2013 ◽  
Vol 280 (1752) ◽  
pp. 20122190 ◽  
Author(s):  
Sharon M. Gourdji ◽  
Ky L. Mathews ◽  
Matthew Reynolds ◽  
José Crossa ◽  
David B. Lobell

Genetic improvements in heat tolerance of wheat provide a potential adaptation response to long-term warming trends, and may also boost yields in wheat-growing areas already subject to heat stress. Yet there have been few assessments of recent progress in breeding wheat for hot environments. Here, data from 25 years of wheat trials in 76 countries from the International Maize and Wheat Improvement Center (CIMMYT) are used to empirically model the response of wheat to environmental variation and assess the genetic gains over time in different environments and for different breeding strategies. Wheat yields exhibited the most sensitivity to warming during the grain-filling stage, typically the hottest part of the season. Sites with high vapour pressure deficit (VPD) exhibited a less negative response to temperatures during this period, probably associated with increased transpirational cooling. Genetic improvements were assessed by using the empirical model to correct observed yield growth for changes in environmental conditions and management over time. These ‘climate-corrected’ yield trends showed that most of the genetic gains in the high-yield-potential Elite Spring Wheat Yield Trial (ESWYT) were made at cooler temperatures, close to the physiological optimum, with no evidence for genetic gains at the hottest temperatures. In contrast, the Semi-Arid Wheat Yield Trial (SAWYT), a lower-yielding nursery targeted at maintaining yields under stressed conditions, showed the strongest genetic gains at the hottest temperatures. These results imply that targeted breeding efforts help us to ensure progress in building heat tolerance, and that intensified (and possibly new) approaches are needed to improve the yield potential of wheat in hot environments in order to maintain global food security in a warmer climate.

2021 ◽  
Author(s):  
Ramandeep Kaur ◽  
Guriqbal Singh Dhillon ◽  
Amandeep Kaur ◽  
Sarabjit Kaur ◽  
Puneetinder Kaur ◽  
...  

1BL/1RS translocation is widely used around the world to enhance wheat yield potential, resistance to various diseases, and adaptation. However, the translocation is combined with inherent quality problems associated with reduced dough strength and dough stickiness due to the presence of Sec-1 on proximal end and absence of GluB3/GliB1 on distal end. Two NILs, one carrying the distal (1RSRW) and the other carrying the proximal (1RSWR) fragment from 1BS, in background of Pavon were used for transferring these two loci in yellow rust resistant version of two elite wheat varieties PBW550+Yr5 and DBW17+Yr5. Foreground and background marker assisted selection was done for the Sec-1- and GluB3+ alongwith Lr26/Yr9/Sr31, Pm8 and 1RS loci in the advancing generation. BC2F5:6 NILs with absence of Secalin and presence of GluB3/GliB1 loci were evaluated for two years in replicated yield trial. A positive correlation of thousand grain weight (TGW), harvest index (HI), and tiller number per meter (TNpM) with yield (YD) with significant GxE effect was observed. Further multivariate analysis of these traits contributed maximum to the effective yield. Thirty promising NILs were identified with Sec-1-/GluB3+ alongwith with high yield contributing parameters.


2019 ◽  
Author(s):  
Chao Fu ◽  
Jiuyuan Du ◽  
Zhonghu He ◽  
Xiuling Tian ◽  
Yue Wang ◽  
...  

Abstract Background Wheat is a momentous crop and feeds billions of people in the world. The improvement of wheat yield is very important to ensure world food security. Normal development of grain is the essential guarantee for wheat yield formation. The genetic study of grain phenotype and identification of key genes for grain filling are of great significance upon dissecting the molecular mechanism of wheat grain morphogenesis and yield potential. Results Here we identified a pair of defective kernel (Dek) isogenic lines, BL31 and BL33, with plump and shrunken mature grains, respectively, and constructed a genetic population from the BL31/BL33 cross. Ten chromosomes had higher frequency of polymorphic single nucleotide polymorphism (SNP) markers between BL31 and BL33 using Wheat660K chip. Totally 783 simple sequence repeat (SSR) markers were chosen from the above chromosomes and 15 of these were integrated into two linkage groups using the genetic population. Genetic mapping identified three QTL, QDek.caas-3BS.1, QDek.caas-3BS.2 and QDek.caas-4AL, explaining 14.78 - 18.17%, 16.61 - 21.83% and 19.08 - 28.19% of phenotypic variances, respectively. Additionally, five polymorphic SNPs from Wheat660K were successfully converted into cleaved amplified polymorphic sequence (CAPS) markers and enriched the target regions of the above QTL. Biochemical analyses revealed that BL33 has significantly higher grain sucrose contents at filling stages and lower mature grain starch contents than BL31, indicating that the Dek QTL may be involved in carbohydrate metabolism. As such, the candidate genes for each QTL were determined according to International Wheat Genome Sequence Consortium (IWGSC) RefSeq v1.0. Conclusions Overall, we achieved a rapid QTL mapping and reasonable predication of causal genes for Dek, laying foundation to conduct fine mapping and dissect the regulatory mechanism underlying Dek trait in wheat.


2019 ◽  
Author(s):  
Chao Fu ◽  
Jiuyuan Du ◽  
Xiuling Tian ◽  
Zhonghu He ◽  
Luping Fu ◽  
...  

Abstract Background Wheat is a momentous crop and feeds billions of people in the world. The improvement of wheat yield is very important to ensure world food security. Normal development of grain is the essential guarantee for wheat yield formation. The genetic study of grain phenotype and identification of key genes for grain filling are of great significance upon dissecting the molecular mechanism of wheat grain morphogenesis and yield potential. Results Here we identified a pair of defective kernel (Dek) isogenic lines, BL31 and BL33, with plump and shrunken mature grains, respectively, and constructed a genetic population from the BL31/BL33 cross. Ten chromosomes had higher frequency of polymorphic single nucleotide polymorphism (SNP) markers between BL31 and BL33 using Wheat660K chip. Totally 783 simple sequence repeat (SSR) markers were chosen from the above chromosomes and 15 of these were integrated into two linkage groups using the genetic population. Genetic mapping identified three QTL, QDek.caas-3BS.1, QDek.caas-3BS.2 and QDek.caas-4AL, explaining 14.78 - 18.17%, 16.61 - 21.83% and 19.08 - 28.19% of phenotypic variances, respectively. Additionally, five polymorphic SNPs from Wheat660K were successfully converted into cleaved amplified polymorphic sequence (CAPS) markers and enriched the target regions of the above QTL. Biochemical analyses revealed that BL33 has significantly higher grain sucrose contents at filling stages and lower mature grain starch contents than BL31, indicating that the Dek QTL may be involved in carbohydrate metabolism. As such, the candidate genes for each QTL were determined according to International Wheat Genome Sequence Consortium (IWGSC) RefSeq v1.0. Conclusions Overall, we achieved a rapid QTL mapping and reasonable predication of causal genes for Dek, laying foundation to conduct fine mapping and dissect the regulatory mechanism underlying Dek trait in wheat.


2020 ◽  
Vol 8 (1) ◽  
pp. 387
Author(s):  
Denise Maria Grzegozewski ◽  
Elizabeth Giron Cima ◽  
Miguel Angel Uribe-Opazo ◽  
Luciana Pagliosa Carvalho Guedes ◽  
Jerry Adriani Johann

In this work, the aim was to evaluate the existence of spatial association of the municipal average official soybean yield (t ha-1) with agrometeorological data and vegetation indices. The information was observed by ten-day periods, in crop years 2010/2011, 2011/2012 and 2012/2013 in the State of Paraná. Local univariate spatial correlation (LISA index), as well as global bivariate correlation (L statistics) were calculated. With this study, we identified neighboring municipalities with high yield in the West as well as municipalities that are located with low-low yield Northwestern, showing positive spatial autocorrelation (IMG=1), significative (p-value < 0.05). In addition, there were differences between seeding times in different regions, and climate irregularity during flowering periods and grain filling in crop year 2011/2012 throughout the state, which caused a large drop in production in all municipalities of the state of Paraná. The analysis of local spatial association showed that in the three crop years, the Northwest region presented a significant low yield potential of soybean (p-value < 0.05). In addition, it was observed that the period from the 3rd ten-day period of October to the 2nd ten-day period of January was essential for the soybean cycle in the different regions of the state, since this period encompasses the critical phases of crop. Differences were also observed between the crop years studied, regarding the agrometeorological variables, which affected soybean yield mainly in the Western region of Paraná – Brazil.


2019 ◽  
Vol 20 (10) ◽  
Author(s):  
Miftahur Rizqi Akbar ◽  
Bambang Sapta Purwoko ◽  
Iswari Saraswati Dewi ◽  
Willy Bayuardi Suwarno ◽  
Sugiyanta

Abstract. Akbar MR, Purwoko BS, Dewi IS, Suwarno WB, Sugiyanta. 2019. Short Communication: Selection of doubled haploid lines of rainfed lowland rice in preliminary yield trial. Biodiversitas 20: 2796-2801. Yield trial is an important step in rice breeding program. This research was aimed at evaluating agronomic characters and selecting the best doubled haploid rainfed rice lines for next advanced yield trial. An experiment was conducted in Indramayu from March to August 2017. The research was arranged in randomized complete block design (RCBD) with three replications. Materials used were fifty-eight doubled haploid lines and two check varieties namely Ciherang and Inpari 18. The results revealed that all observed characters had broad genetic variability and high heritability. The number of productive tillers and the number of filled grains per panicle had a positive correlation and direct effect on productivity. Based on index selection, thirty lines were selected to have good agronomic characters and high yield. These lines had characteristics of plant height (85.7-124.7 cm), number of productive tillers (8.6-14.8 tillers), day to harvest (104.0-117.3 days), number of filled grains per panicle (136.7-264.7 grains), number of total grains per panicle (152.0-305.7 grains), weight of 1000 grain (21.5-31.3 g), and productivity (4.1-6.8 tons ha-1). Keywords: good agronomic trait, high yield potential, selection index


2019 ◽  
Author(s):  
Chao Fu ◽  
Jiuyuan Du ◽  
Xiuling Tian ◽  
Zhonghu He ◽  
Luping Fu ◽  
...  

Abstract Background Wheat is a momentous crop and feeds billions of people in the world. The improvement of wheat yield is very important to ensure world food security. Normal development of grain is the essential guarantee for wheat yield formation. The genetic study of grain phenotype and identification of key genes for grain filling are of great significance upon dissecting the molecular mechanism of wheat grain morphogenesis and yield potential. Results Here we identified a pair of defective kernel (Dek) isogenic lines, BL31 and BL33, with plump and shrunken mature grains, respectively, and constructed a genetic population from the BL31/BL33 cross. Ten chromosomes had higher frequency of polymorphic single nucleotide polymorphism (SNP) markers between BL31 and BL33 using Wheat660K chip. Totally 783 simple sequence repeat (SSR) markers were chosen from the above chromosomes and 15 of these were integrated into two linkage groups using the genetic population. Genetic mapping identified three QTL, QDek.caas-3BS.1, QDek.caas-3BS.2 and QDek.caas-4AL, explaining 14.78 - 18.17%, 16.61 - 21.83% and 19.08 - 28.19% of phenotypic variances, respectively. Additionally, five polymorphic SNPs from Wheat660K were successfully converted into cleaved amplified polymorphic sequence (CAPS) markers and enriched the target regions of the above QTL. Biochemical analyses revealed that BL33 has significantly higher grain sucrose contents at filling stages and lower mature grain starch contents than BL31, indicating that the Dek QTL may be involved in carbohydrate metabolism. As such, the candidate genes for each QTL were determined according to International Wheat Genome Sequence Consortium (IWGSC) RefSeq v1.0. Conclusions Overall, we achieved a rapid QTL mapping and reasonable predication of causal genes for Dek, laying foundation to conduct fine mapping and dissect the regulatory mechanism underlying Dek trait in wheat.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Chao Fu ◽  
Jiuyuan Du ◽  
Xiuling Tian ◽  
Zhonghu He ◽  
Luping Fu ◽  
...  

Abstract Background Wheat is a momentous crop and feeds billions of people in the world. The improvement of wheat yield is very important to ensure world food security. Normal development of grain is the essential guarantee for wheat yield formation. The genetic study of grain phenotype and identification of key genes for grain filling are of great significance upon dissecting the molecular mechanism of wheat grain morphogenesis and yield potential. Results Here we identified a pair of defective kernel (Dek) isogenic lines, BL31 and BL33, with plump and shrunken mature grains, respectively, and constructed a genetic population from the BL31/BL33 cross. Ten chromosomes had higher frequency of polymorphic single nucleotide polymorphism (SNP) markers between BL31 and BL33 using Wheat660K chip. Totally 783 simple sequence repeat (SSR) markers were chosen from the above chromosomes and 15 of these were integrated into two linkage groups using the genetic population. Genetic mapping identified three QTL, QDek.caas-3BS.1, QDek.caas-3BS.2 and QDek.caas-4AL, explaining 14.78–18.17%, 16.61–21.83% and 19.08–28.19% of phenotypic variances, respectively. Additionally, five polymorphic SNPs from Wheat660K were successfully converted into cleaved amplified polymorphic sequence (CAPS) markers and enriched the target regions of the above QTL. Biochemical analyses revealed that BL33 has significantly higher grain sucrose contents at filling stages and lower mature grain starch contents than BL31, indicating that the Dek QTL may be involved in carbohydrate metabolism. As such, the candidate genes for each QTL were predicated according to International Wheat Genome Sequence Consortium (IWGSC) RefSeq v1.0. Conclusions Three major QTL for Dek were identified and their causal genes were predicted, laying a foundation to conduct fine mapping and dissect the regulatory mechanism underlying Dek trait in wheat.


2007 ◽  
Vol 145 (1) ◽  
pp. 17-29 ◽  
Author(s):  
M. J. FOULKES ◽  
J. W. SNAPE ◽  
V. J. SHEARMAN ◽  
M. P. REYNOLDS ◽  
O. GAJU ◽  
...  

Knowledge of the changes in physiological traits associated with genetic gains in yield potential is essential to improve understanding of yield-limiting factors and to inform future breeding strategies. Recent advances in genetic yield potential and associated physiological changes in wheat (Triticum aestivum L.) are reviewed. Genetic gains in yield potential worldwide have been both positively correlated with harvest index (HI) and above-ground dry matter (AGDM), with more frequent reports of yield progress associated with biomass since about 1990. It is concluded that an important aim of future breeding will be the increase of biomass production while maintaining the present values of HI. In winter wheat recent biomass progress has been positively associated with pre-anthesis radiation-use efficiency (RUE) and water-soluble carbohydrate (WSC) content of stems at anthesis. Present results in two doubled-haploid (DH) populations show a positive linear relationship between stem WSC and grain yield in the UK environment. Results from various investigations worldwide in recent years have demonstrated that biomass increases have been associated with particular introductions of alien genes into wheat germplasm, e.g. the 1BL.1RS wheat-rye translocation and the 7DL.7Ag wheat-Agropyron elongatum translocation. Present results confirm a positive effect of 1BL.1RS on harvest biomass in two DH populations in the UK. The future prospects for identifying physiological traits to raise yield potential are considered with particular reference to winter wheat grown in northwestern Europe. It is proposed that optimized rooting traits, an extended stem-elongation phase, greater RUE, greater stem WSC storage and optimized ear morphology will be important for breeding progress in yield potential in future years.


1991 ◽  
Vol 116 (1) ◽  
pp. 23-36 ◽  
Author(s):  
E. Acevedo ◽  
P. Q. Craufurd ◽  
R. B. Austin ◽  
P. Pérez-Marco

SUMMARYResults are reported from nine field trials carried out in 1985/86 and 1986/87 aimed at identifying plant traits which are associated with high yield in barley in low-rainfall Mediterranean areas. Thirtyseven two-rowed and 35 six-rowed genotypes, representing the known diversity in traits considered to be useful, were compared in trials at three sites differing in expected annual rainfall (212–328 mm) in northern Syria, and in droughted and irrigated trials at Cambridge, UK. Yield, its components and other morphological and developmental traits were measured and correlations calculated.Grain yields of the two- and six-rowed groups of genotypes were similar at all sites except in the irrigated trial in Cambridge, where the six-rowed genotypes gave the highest yield. Aside from the known difference in number of ears and number of grains/ear between two- and six-rowed genotypes, the simple correlations between grain yield and measured traits suggested that important traits for high yield in two- and six-rowed genotypes in dry environments were prostrate habit, vigorous seedling growth, good ground cover, early ear emergence, many ears/m2 and large grains. In the two-rowed genotypes, short stature and a short grain-filling period were also important, while in the six-rowed genotypes, tall stature, high straw yield, many grains/ear and long peduncles were important. Correlations of these characters with an index of drought susceptibility and with yield adjusted for yield potential and date of ear emergence supported the conclusions based on the simple correlations.The physiological basis of the correlated traits is discussed and the implications for breeding are considered.


2017 ◽  
Vol 54 (6) ◽  
pp. 805-823 ◽  
Author(s):  
B. BADU-APRAKU ◽  
M. A. B. FAKOREDE ◽  
B. ANNOR ◽  
A. O. TALABI

SUMMARYMaize (Zea mays L.) is the most important staple crop in West and Central Africa (WCA), but its production is severely constrained by low soil nitrogen (low N). Fifty-six extra-early open-pollinated maize cultivars developed during three breeding eras, 1995–2000, 2001–2006 and 2007–2012, were evaluated under low N and high soil nitrogen (high N) at two locations in Nigeria in 2013 and 2014, to investigate the genetic gains in grain yield and identify outstanding cultivars. During the first breeding era, the emphasis of the programme was on breeding for resistance to the maize streak virus (MSV) and high yield potential, while the major breeding emphasis during the second era was on recurrent selection for improved grain yield and Striga resistance in two extra-early-maturing source populations, TZEE-W Pop STR (white) and TZEE-Y Pop STR (yellow). Starting from the third era, the source populations were subjected to improvement for tolerance to drought, low N and resistance to Striga. A randomized incomplete block design with two replications was used for the field evaluations. Results revealed genetic gains in grain yield of 0.314 Mg ha−1 (13.29%) and 0.493 Mg ha−1 (16.84%) per era under low N and high N, respectively. The annual genetic gains in grain yield was 0.054 Mg ha–1 (2.14%) under low N and 0.081 Mg ha–1 (2.56%) under high N environments. The cultivar 2009 TZEE-OR2 STR of era 3 was the most stable, with competitive yield across environments, while 2004 TZEE-W Pop STR C4 from era 2, and TZEE-W STR 104, TZEE-W STR 108 and 2012 TZEE-W DT STR C5 from era 3 were high yielding but less stable. These cultivars should be further tested on-farm and commercialized in WCA. Substantial progress has been made in breeding for high grain yield and low-N tolerance in the sub-region.


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