Yield improvement of oilseed rape (Brassica napus L.) in a low rainfall environment. I. Utilization of genes for early flowering in primary and secondary gene pools

1992 ◽  
Vol 43 (3) ◽  
pp. 609 ◽  
Author(s):  
N Thurling ◽  
R Kaveeta

The extent to which time to flowering of a Brassica napus commercial cultivar could be reduced through utilization of genes in its primary and secondary pools was examined with particular reference to yield improvement in lower rainfall environments. The B. napus breeding line RU2 and the B. campestris population Chinoli C42, which were used as sources of early flowering genes to be incorporated into the commercial B. napus cultivar Wesbrook, flowered significantly earlier than Wesbrook with or without vernalization and/or long days. In the cross of Wesbrook with RU2, the substantial variation in flowering time in the F2 was highly heritable (hn2 = 0.79), and some plants in the F2 and first backcross to Wesbrook flowered earlier than the early flowering parent RU2. Many lines flowering much earlier than Wesbrook were still obtained after two generations of recurrent backcrossing to Wesbrook and subsequent selfing without selection at any stage. Variation in flowering time among these lines primarily reflected differences in growth rate as measured by the rate of leaf node development. F2 plants derived from the cross between Wesbrook and the B. campestris population Chinoli C42 varied widely in chromosome number and flowering time, but there was no relationship between pre-anthesis development and chromosome number. Two generations of recurrent backcrossing to Wesbrook and subsequent selfing without selection at any stage produced a series of lines all having the normal B. napus chromosome complement. All these lines flowered significantly earlier than Wesbrook, and the earliest flowering line flowered at the same time as the early flowering B. campestris parent. The implications of these results are discussed with particular reference to developing agronomically superior B. napus cultivars closely adapted to lower rainfall environments in the Western Australian wheatbelt and elsewhere in southern Australia.

1992 ◽  
Vol 43 (3) ◽  
pp. 623
Author(s):  
N Thurling ◽  
R Kaveeta

Agronomic characteristics of two groups of early flowering Brassica napus lines and their respective parents were compared at East Beverley in the Western Australian wheatbelt. These lines had been derived through two generations of backcrossing and subsequent selfing from crosses of the B. napus cultivar Wesbrook (recurrent parent) with an early flowering B. napus line RU2 and an even earlier flowering B. campestris population Chinoli C42. Lines selected for this experiment had flowered earliest in a previous controlled environment experiment. Only RU2 and one WesbrookxRU2 line (IB72) had significantly higher yields than Wesbrook (149% and 166% respectively), and one Wesbrookxchinoli C42 line was the only line to have a significantly lower yield than Wesbrook. None of the lines had significantly higher yields than their respective non-recurrent parents. Although RU2 and IB72 flowered much earlier than Wesbrook, there was no significant relationship between flowering time and seed yield over all lines. Lines which were the earliest to commence stem elongation tended to have higher seed yields. However, of all the growth and development characters measured, the biological yield and the dry weight increment between commencement of flowering and maturity were most closely related to seed yield. RU2 and IB72 accumulated far more dry matter over the post-anthesis period than Wesbrook and all other lines except another WesbrookxRU2 line. The superior post-anthesis growth of RU2 and IB72 may simply be a manifestation of the longer period available for growth under more favourable environmental conditions or deeper roots extracting more water from a greater depth. However, since there was no relationship between flowering time and the post-anthesis dry matter increment, it seems more likely that IB72 has received genes for superior post-anthesis growth as well as those determining early flowering from RU2. Given the rapid decline in soil moisture availability during post-anthesis development in this environment, these genes may affect post-anthesis growth through determining a greater capacity for drought avoidance. The implications of these results are discussed with particular reference to the breeding of higher yielding B. napus cultivars for lower rainfall environments.


2020 ◽  
Author(s):  
Oumar Diack ◽  
Ghislain Kanfany ◽  
Mame Codou Gueye ◽  
Ousmane Sy ◽  
Amadou Fofana ◽  
...  

Abstract Background: Pearl millet, a dietary food for around 100 million people in Africa and in India, has a large diversity due to an extensive genetic diversity combined with a high degree of admixture with wild relatives. In Senegal, two major morphotypes are distinguished: early-flowering and late-flowering millets. The phenotypic variabilities according to the flowering time plays an important role in pearl millet adaptation to climate variability. A better understanding of the genetic makeup of these variabilities would allow breeding of pearl millet fitting different climatic areas. In this study, we aimed to characterize the genetic basis of these phenotypic differences. Results: We defined a core collection capturing most of the diversity of cultivated pearl millet of Senegal, which includes 60 early-flowering Souna and 31 late-flowering Sanio. This panel was evaluated during the 2016 and 2017 rainy seasons at Nioro for 16 agro-morphological traits. Phenological and phenotypic traits linked with yield, flowering time, and biomass helped differentiated early- and late-flowering millets. Further, using genotyping-by-sequencing (GBS), 21,663 single nucleotide polymorphisms (SNPs) with minor allele frequencies of more than 5% were identified. Sparse Non-Negative Matrix Factorization (sNMF) analysis confirms the genetic structure in two gene pools associated with flowering time differences. Moreover, two chromosomal regions on linkage groups (LG 3) (~89.7Mb) and (LG 6) (~68.1Mb) differentiated the early-flowering into two clusters. Genome-wide association study (GWAS) was used to associate phenotypic variation to the SNPs and 18 genes were linked to flowering time, plant height, nodal tiller number, and biomass (P-value ˂ 2.3E-06). Conclusions: The diversity of early- and late-flowering pearl millet landraces of Senegal was captured using a heuristic approach. Key phenology and phenotypic traits, SNPs, and candidate genes underlying flowering time, tillering, biomass and plant height of pearl millet were identified. Chromosome rearrangements in LG3 and LG6 were implicated as a source of variation in early-flowering morphotypes. Using candidate genes underlying these features between pearl millet morphotypes would have paramount importance in breeding strategies under climate change scenarios.


BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Oumar Diack ◽  
Ghislain Kanfany ◽  
Mame Codou Gueye ◽  
Ousmane Sy ◽  
Amadou Fofana ◽  
...  

Abstract Background Pearl millet, a nutritious food for around 100 million people in Africa and India, displays extensive genetic diversity and a high degree of admixture with wild relatives. Two major morphotypes can be distinguished in Senegal: early-flowering Souna and late-flowering Sanio. Phenotypic variabilities related to flowering time play an important role in the adaptation of pearl millet to climate variability. A better understanding of the genetic makeup of these variabilities would make it possible to breed pearl millet to suit regions with different climates. The aim of this study was to characterize the genetic basis of these phenotypic differences. Results We defined a core collection that captures most of the diversity of cultivated pearl millets in Senegal and includes 60 early-flowering Souna and 31 late-flowering Sanio morphotypes. Sixteen agro-morphological traits were evaluated in the panel in the 2016 and 2017 rainy seasons. Phenological and phenotypic traits related with yield, flowering time, and biomass helped differentiate early- and late-flowering morphotypes. Further, using genotyping-by-sequencing (GBS), 21,663 single nucleotide polymorphisms (SNPs) markers with more than 5% of minor allele frequencies were discovered. Sparse non-negative matrix factorization (sNMF) analysis confirmed the genetic structure in two gene pools associated with differences in flowering time. Two chromosomal regions on linkage groups (LG 3) (~ 89.7 Mb) and (LG 6) (~ 68.1 Mb) differentiated two clusters among the early-flowering Souna. A genome-wide association study (GWAS) was used to link phenotypic variation to the SNPs, and 18 genes were linked to flowering time, plant height, tillering, and biomass (P-value < 2.3E-06). Conclusions The diversity of early- and late-flowering pearl millet morphotypes in Senegal was captured using a heuristic approach. Key phenological and phenotypic traits, SNPs, and candidate genes underlying flowering time, tillering, biomass yield and plant height of pearl millet were identified. Chromosome rearrangements in LG3 and LG6 were inferred as a source of variation in early-flowering morphotypes. Using candidate genes underlying these features between pearl millet morphotypes will be of paramount importance in breeding for resilience to climatic variability.


2012 ◽  
Vol 7 (3) ◽  
pp. 231-237 ◽  
Author(s):  
Joon Ki Hong ◽  
Soo-Yun Kim ◽  
Kwang-Soo Kim ◽  
Soo-Jin Kwon ◽  
Jung Sun Kim ◽  
...  

2020 ◽  
Author(s):  
Oumar Diack ◽  
Ghislain Kanfany ◽  
Mame Codou Gueye ◽  
Ousmane Sy ◽  
Amadou Fofana ◽  
...  

Abstract Background Pearl millet, a dietary food for around 100 million people in Africa and in India, has a large diversity due to an extensive genetic diversity combined with a high degree of admixture with wild relatives. In Senegal, two major morphotypes are distinguished: early-flowering and late-flowering millets. The phenotypic variabilities according to the flowering time plays an important role in pearl millet adaptation to climate variability. A better understanding of the genetic makeup of these variabilities would allow breeding of pearl millet fitting different climatic areas. In this study, we aimed to characterize the genetic basis of these phenotypic differences. Results We defined a core collection capturing most of the diversity of cultivated pearl millet of Senegal, which includes 60 early-flowering Souna and 31 late-flowering Sanio. This panel was evaluated during the 2016 and 2017 rainy seasons at Nioro for 16 agro-morphological traits. Phenological and phenotypes traits linked with yield, flowering time, and biomass helped differentiated early- and late-flowering millets. Further, using genotyping-by-sequencing (GBS), 21,663 single nucleotide polymorphisms (SNPs) with minor allele frequencies of more than 5% were identified. Sparse Non-Negative Matrix Factorization (sNMF) analysis confirms the genetic structure in 2 gene pools associated with flowering time differences. Moreover, 2 chromosomal regions on linkage groups 3 (~ 89.7 Mb) and 6 (~ 68.1 Mb) differentiated the early-flowering into 2 clusters. Genome-wide analysis study (GWAS) was used to associate phenotypic variation to the SNPs and 18 genes were linked to flowering time, plant height, nodal tiller number, and biomass (P-value ˂ 2.3E-06). Conclusions The diversity of early- and late-flowering pearl millet landraces of Senegal was captured using a heuristic approach. Key phenology and phenotypic traits, SNPs, ad candidate genes underlying flowering time, tillering, biomass and plant height of pearl millet were identified. Chromosome rearrangements in LG 3 and 6 were implicated as a source of variation in early-flowering morphotypes. Using candidate genes underlying these features between pearl millet morphotypes would have paramount importance in breeding strategies under climate change scenarios.


2020 ◽  
Author(s):  
Oumar Diack ◽  
Ghislain Kanfany ◽  
Mame Codou Gueye ◽  
Ousmane Sy ◽  
Amadou Fofana ◽  
...  

Abstract Background: Pearl millet, a nutritious food for around 100 million people in Africa and India, displays extensive genetic diversity and a high degree of admixture with wild relatives. Two major morphotypes can be distinguished in Senegal: early-flowering Souna and late-flowering Sanio. Phenotypic variabilities related to flowering time play an important role in the adaptation of pearl millet to climate variability. A better understanding of the genetic makeup of these variabilities would make it possible to breed pearl millet to suit regions with different climates. The aim of this study was to characterize the genetic basis of these phenotypic differences.Results: We defined a core collection that captures most of the diversity of cultivated pearl millets in Senegal and includes 60 early-flowering Souna and 31 late-flowering Sanio morphotypes. Sixteen agro-morphological traits were evaluated in the panel in the 2016 and 2017 rainy seasons. Phenological and phenotypic traits related with yield, flowering time, and biomass helped differentiate early- and late-flowering morphotypes. Further, using genotyping-by-sequencing (GBS), 21,663 single nucleotide polymorphisms (SNPs) markers with more than 5% of minor allele frequencies were discovered. Sparse non-negative matrix factorization (sNMF) analysis confirmed the genetic structure in two gene pools associated with differences in flowering time. Two chromosomal regions on linkage groups (LG 3) (~89.7Mb) and (LG 6) (~68.1Mb) differentiated two clusters among the early-flowering Souna. A genome-wide association study (GWAS) was used to link phenotypic variation to the SNPs, and 18 genes were linked to flowering time, plant height, tillering, and biomass (P-value ˂ 2.3E-06).Conclusions: The diversity of early- and late-flowering pearl millet morphotypes in Senegal was captured using a heuristic approach. Key phenological and phenotypic traits, SNPs, and candidate genes underlying flowering time, tillering, biomass yield and plant height of pearl millet were identified. Chromosome rearrangements in LG3 and LG6 were inferred as a source of variation in early-flowering morphotypes. Using candidate genes underlying these features between pearl millet morphotypes will be of paramount importance in breeding for resilience to climatic variability.


2020 ◽  
Author(s):  
Oumar Diack ◽  
Ghislain Kanfany ◽  
Mame Codou Gueye ◽  
Ousmane Sy ◽  
Amadou Fofana ◽  
...  

Abstract Background: Pearl millet, a nutritious food for around 100 million people in Africa and India, displays extensive genetic diversity and a high degree of admixture with wild relatives. Two major morphotypes can be distinguished in Senegal: early-flowering Souna and late-flowering Sanio. Phenotypic variabilities related to flowering time play an important role in the adaptation of pearl millet to climate variability. A better understanding of the genetic makeup of these variabilities would make it possible to breed pearl millet to suit regions with different climates. The aim of this study was to characterize the genetic basis of these phenotypic differences.Results: We defined a core collection that captures most of the diversity of cultivated pearl millets in Senegal and includes 60 early-flowering Souna and 31 late-flowering Sanio morphotypes. Sixteen agro-morphological traits were evaluated in the panel in the 2016 and 2017 rainy seasons. Phenological and phenotypic traits related with yield, flowering time, and biomass helped differentiate early- and late-flowering morphotypes. Further, using genotyping-by-sequencing (GBS), 21,663 single nucleotide polymorphisms (SNPs) markers with more than 5% of minor allele frequencies were discovered. Sparse non-negative matrix factorization (sNMF) analysis confirmed the genetic structure in two gene pools associated with differences in flowering time. Two chromosomal regions on linkage groups (LG 3) (~89.7Mb) and (LG 6) (~68.1Mb) differentiated two clusters among the early-flowering Souna. A genome-wide association study (GWAS) was used to link phenotypic variation to the SNPs, and 18 genes were linked to flowering time, plant height, tillering, and biomass (P-value ˂ 2.3E-06).Conclusions: The diversity of early- and late-flowering pearl millet morphotypes in Senegal was captured using a heuristic approach. Key phenological and phenotypic traits, SNPs, and candidate genes underlying flowering time, tillering, biomass yield and plant height of pearl millet were identified. Chromosome rearrangements in LG3 and LG6 were inferred as a source of variation in early-flowering morphotypes. Using candidate genes underlying these features between pearl millet morphotypes will be of paramount importance in breeding for resilience to climatic variability.


2020 ◽  
Vol 36 (6) ◽  
pp. 49-54
Author(s):  
A.A. Nalbandyan ◽  
T.P. Fedulova ◽  
I.V. Cherepukhina ◽  
T.I. Kryukova ◽  
N.R. Mikheeva ◽  
...  

The flowering time control gene of various sugar beet plants has been studied. The BTC1 gene is a regulator for the suppressor (flowering time 1) and inducer (flowering time 2) genes of this physiological process. The F9/R9 primer pair was used for polymerase chain reaction; these primers are specific to the BTC1 gene region containing exon 9, as well as intron and exon 10. For the first time, nucleotide substitutions in exon 10 of BTC1 gene were identified in bolting sensitive samples (HF1 and BF1), which led to a change in the amino acid composition of the coded polypeptide chain. Based on the results of bioinformatic analysis, it can be assumed that certain nucleotide polymorphisms in the BTC1 gene may determine with a high probability the predisposition of sugar beet genotypes to early flowering. The use of the Geneious Prime tool for the analysis of the BTC1 gene sequences may allow the culling of genotypes prone to early flowering at early stages of selection. sugar beet, flowering gene, BTC1, genetic polymorphism, PCR, molecular genetic markers, selection


2021 ◽  
Vol 22 (8) ◽  
pp. 3856
Author(s):  
Sandra Rychel-Bielska ◽  
Anna Surma ◽  
Wojciech Bielski ◽  
Bartosz Kozak ◽  
Renata Galek ◽  
...  

White lupin (Lupinus albus L.) is a pulse annual plant cultivated from the tropics to temperate regions for its high-protein grain as well as a cover crop or green manure. Wild populations are typically late flowering and have high vernalization requirements. Nevertheless, some early flowering and thermoneutral accessions were found in the Mediterranean basin. Recently, quantitative trait loci (QTLs) explaining flowering time variance were identified in bi-parental population mapping, however, phenotypic and genotypic diversity in the world collection has not been addressed yet. In this study, a diverse set of white lupin accessions (n = 160) was phenotyped for time to flowering in a controlled environment and genotyped with PCR-based markers (n = 50) tagging major QTLs and selected homologs of photoperiod and vernalization pathway genes. This survey highlighted quantitative control of flowering time in white lupin, providing statistically significant associations for all major QTLs and numerous regulatory genes, including white lupin homologs of CONSTANS, FLOWERING LOCUS T, FY, MOTHER OF FT AND TFL1, PHYTOCHROME INTERACTING FACTOR 4, SKI-INTERACTING PROTEIN 1, and VERNALIZATION INDEPENDENCE 3. This revealed the complexity of flowering control in white lupin, dispersed among numerous loci localized on several chromosomes, provided economic justification for future genome-wide association studies or genomic selection rather than relying on simple marker-assisted selection.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dongmei Ma ◽  
Bei Liu ◽  
Lingqiao Ge ◽  
Yinyin Weng ◽  
Xiaohui Cao ◽  
...  

Abstract Background Alfalfa (Medicago sativa L.) is a perennial legume extensively planted throughout the world as a high nutritive value livestock forage. Flowering time is an important agronomic trait that contributes to the production of alfalfa hay and seeds. However, the underlying molecular mechanisms of flowering time regulation in alfalfa are not well understood. Results In this study, an early-flowering alfalfa genotype 80 and a late-flowering alfalfa genotype 195 were characterized for the flowering phenotype. Our analysis revealed that the lower jasmonate (JA) content in new leaves and the downregulation of JA biosynthetic genes (i.e. lipoxygenase, the 12-oxophytodienoate reductase-like protein, and salicylic acid carboxyl methyltransferase) may play essential roles in the early-flowering phenotype of genotype 80. Further research indicated that genes encode pathogenesis-related proteins [e.g. leucine rich repeat (LRR) family proteins, receptor-like proteins, and toll-interleukin-like receptor (TIR)-nucleotide-binding site (NBS)-LRR class proteins] and members of the signaling receptor kinase family [LRR proteins, kinases domain of unknown function 26 (DUF26) and wheat leucine-rich repeat receptor-like kinase10 (LRK10)-like kinases] are related to early flowering in alfalfa. Additionally, those involved in secondary metabolism (2-oxoglutarate/Fe (II)-dependent dioxygenases and UDP-glycosyltransferase) and the proteasome degradation pathway [really interesting new gene (RING)/U-box superfamily proteins and F-box family proteins] are also related to early flowering in alfalfa. Conclusions Integrated phenotypical, physiological, and transcriptomic analyses demonstrate that hormone biosynthesis and signaling pathways, pathogenesis-related genes, signaling receptor kinase family genes, secondary metabolism genes, and proteasome degradation pathway genes are responsible for the early flowering phenotype in alfalfa. This will provide new insights into future studies of flowering time in alfalfa and inform genetic improvement strategies for optimizing this important trait.


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