scholarly journals Fine Mapping and Genetic Interactions of Nearly-Isogenic Allelic Series Representing Yield and Quality QTLs Derived from Wild Tomato Species

Author(s):  
Dani Zamir ◽  
Steven Tanksley

Wild germplasm represents a rich source of QTLs capable of enhancing productivity of crop plants. Using the molecular linkage map of tomato in conjunction with novel population structures, we have identified QTLs from five Lycopersicon species that improve key yield and quality associated traits of processing tomatoes. In this research we employed multi-testing sites for fine mapping analysis of the different components of the affected traits combined with genetic interaction studies. Our results demonstrate that 'exotic libraries', which comprise of marker-defined genomic regions taken from wild species and introgressed onto the background of elite crop lines, provide an important opportunity for improving of the agricultural performance of modem crop varieties. Furthermore, we showed that these genetic resources can also serve as reagents for the discovery and characterization of genes that underlie traits of agricultural value. The results set the stage for using the QTLs in marker assisted programs and for applying map-based cloning of the targeted QTL/genes. The cloning of QTLs revealed genes that control pathways for agricultural yield in tomato that may be common for other crop species.

Euphytica ◽  
2004 ◽  
Vol 135 (3) ◽  
pp. 283-296 ◽  
Author(s):  
Heather E. Yates ◽  
Anne Frary ◽  
Sami Doganlar ◽  
Anna Frampton ◽  
Nancy T. Eannetta ◽  
...  

Genetics ◽  
2000 ◽  
Vol 156 (2) ◽  
pp. 763-774 ◽  
Author(s):  
Willis Li ◽  
Elizabeth Noll ◽  
Norbert Perrimon

Abstract Raf is an essential downstream effector of activated p21Ras (Ras) in transducing proliferation or differentiation signals. Following binding to Ras, Raf is translocated to the plasma membrane, where it is activated by a yet unidentified “Raf activator.” In an attempt to identify the Raf activator or additional molecules involved in the Raf signaling pathway, we conducted a genetic screen to identify genomic regions that are required for the biological function of Drosophila Raf (Draf). We tested a collection of chromosomal deficiencies representing ∼70% of the autosomal euchromatic genomic regions for their abilities to enhance the lethality associated with a hypomorphic viable allele of Draf, DrafSu2. Of the 148 autosomal deficiencies tested, 23 behaved as dominant enhancers of Draf  Su2, causing lethality in Draf  Su2 hemizygous males. Four of these deficiencies identified genes known to be involved in the Drosophila Ras/Raf (Ras1/Draf) pathway: Ras1, rolled (rl, encoding a MAPK), 14-3-3ϵ, and bowel (bowl). Two additional deficiencies removed the Drosophila Tec and Src homologs, Tec29A and Src64B. We demonstrate that Src64B interacts genetically with Draf and that an activated form of Src64B, when overexpressed in early embryos, causes ectopic expression of the Torso (Tor) receptor tyrosine kinase-target gene tailless. In addition, we show that a mutation in Tec29A partially suppresses a gain-of-function mutation in tor. These results suggest that Tec29A and Src64B are involved in Tor signaling, raising the possibility that they function to activate Draf. Finally, we discovered a genetic interaction between Draf  Su2 and Df(3L)vin5 that revealed a novel role of Draf in limb development. We find that loss of Draf activity causes limb defects, including pattern duplications, consistent with a role for Draf in regulation of engrailed (en) expression in imaginal discs.


2017 ◽  
Vol 41 (2) ◽  
pp. 201-208
Author(s):  
Anni Cristini Silvestri Gomes ◽  
Maria das Graças Cardoso ◽  
Juliano Vilela Resende ◽  
Sérgio Scherrer Thomasi ◽  
Luana Isac Soares ◽  
...  

ABSTRACT One of the main problems facing agriculture is the loss of production as a result of the attack of agricultural pests. Alternative ways to work around this problem are being sought. There are substances called acylsugars that are naturally produced by the wild tomato species S. pennellii and affect arthropod pests. The objectives of this work were to synthesize two acylsugars and assess the biological effect of these on the arthropod pests Bemissia tabaci and Tetranycus urticae. The syntheses were performed via the reactions of glucose and sucrose (saccharose) with acetic anhydride using sodium acetate as the catalyst. The products of these reactions were sucrose octa-acetate and glucose penta-acetate, the structures of which were confirmed by spectroscopic techniques. In a resistance test against the mite, a linear correlation between the concentration of the synthesized substances, and the dislocation of the mite was obtained. A delay in the hatching of the arthropod eggs was observed, causing a mortality rate of approximately 95% in the 1st instar larvae of mites that was confirmed in adults. In the biological tests with Bemisia tabaci, there was a low rate of hatching and emergence, and the effect on the nymphs was the deformation of the emergent adults.


2018 ◽  
Author(s):  
Qingqi Chen ◽  
Xiangyang Xu ◽  
Jingbin Jiang ◽  
Jingfu Li

Tomato yellow leaf curl virus (TYLCV) is one of the most devastating viruses of cultivated tomato in both tropical and subtropical regions. Five major genes (Ty-1, Ty-2, Ty-3, Ty-4 and Ty-5) from wild tomato species have been associated with resistance to TYLCV. Researchers have recently attempted to determine the functions of these resistance genes, but molecular mechanisms underlying the observed resistance remain unclear. Here, resistant (cv. CLN3212A-23, carrying Ty-5) and susceptible (cv. Moneymaker) plants were either left untreated (R and S, respectively) or artificially inoculated with TYLCV via Agrobacterium-mediated transformation (RT and ST, respectively). The transcriptomes of the plants in the four groups were then analyzed by RNA-Seq, and the results identified 8,639 differentially expressed genes (DEGs) between the R and RT groups, 2,818 DEGs between the RT and ST groups, 8,899 DEGs between the S and ST groups, and 707 DEGs between the R and S groups. The gene expression profiles in both the resistant and susceptible tomato cultivars appeared to undergo notable changes after viral inoculation, and functional classification revealed that most DEGs were associated with 18 GO terms. Moreover, the functional classification of the response of Ty-5-carrying tomato plants to TYLCV infection identified the importance of the GO term “response to stimulus” in the BP category, which is related to disease resistance. In addition, 28 genes were significantly enriched in the “Plant hormone signal transduction”, “Carbon metabolism”, “ Carbon fixation in photosynthetic organisms ” and “ Glutathione metabolism ” pathways. The differential expression levels of 12 select genes were confirmed by quantitative real-time PCR. The present study indicates that the Ty-5 gene activates the expression of multiple genes involved in the resistance process and will aid a more in-depth understanding of the effects of the Ty-5 gene on resistance based on its molecular mechanism with the aim of improving TYLCV disease management in tomato.


2021 ◽  
Vol 28 ◽  
Author(s):  
Vinutha Kanuganahalli Somegowda ◽  
Laavanya Rayaprolu ◽  
Abhishek Rathore ◽  
Santosh Pandurang Deshpande ◽  
Rajeev Gupta

: The main focus of this review is to discuss the current status of the use of GWAS for fodder quality and biofuel owing to its similarity of traits. Sorghum is a potential multipurpose crop, popularly cultivated for various uses as food, feed fodder, and biomass for ethanol. Production of a huge quantity of biomass and genetic variation for complex sugars are the main motivation not only to use sorghum as fodder for livestock nutritionists but also a potential candidate for biofuel generation. Few studies have been reported on the knowledge transfer that can be used from the development of biofuel technologies to complement improved fodder quality and vice versa. With recent advances in genotyping technologies, GWAS became one of the primary tools used to identify the genes/genomic regions associated with the phenotype. These modern tools and technologies accelerate the genomic assisted breeding process to enhance the rate of genetic gains. Hence, this mini-review focuses on GWAS studies on genetic architecture and dissection of traits underpinning fodder quality and biofuel traits and their limited comparison with other related model crop species.


Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1026 ◽  
Author(s):  
K. N. S. Usha Kiranmayee ◽  
C. Tom Hash ◽  
S. Sivasubramani ◽  
P. Ramu ◽  
Bhanu Prakash Amindala ◽  
...  

This study was conducted to dissect the genetic basis and to explore the candidate genes underlying one of the important genomic regions on an SBI-10 long arm (L), governing the complex stay-green trait contributing to post-flowering drought-tolerance in sorghum. A fine-mapping population was developed from an introgression line cross—RSG04008-6 (stay-green) × J2614-11 (moderately senescent). The fine-mapping population with 1894 F2 was genotyped with eight SSRs and a set of 152 recombinants was identified, advanced to the F4 generation, field evaluated with three replications over 2 seasons, and genotyped with the GBS approach. A high-resolution linkage map was developed for SBI-10L using 260 genotyping by sequencing—Single Nucleotide Polymorphism (GBS–SNPs). Using the best linear unpredicted means (BLUPs) of the percent green leaf area (%GL) traits and the GBS-based SNPs, we identified seven quantitative trait loci (QTL) clusters and single gene, mostly involved in drought-tolerance, for each QTL cluster, viz., AP2/ERF transcription factor family (Sobic.010G202700), NBS-LRR protein (Sobic.010G205600), ankyrin-repeat protein (Sobic.010G205800), senescence-associated protein (Sobic.010G270300), WD40 (Sobic.010G205900), CPK1 adapter protein (Sobic.010G264400), LEA2 protein (Sobic.010G259200) and an expressed protein (Sobic.010G201100). The target genomic region was thus delimited from 15 Mb to 8 genes co-localized with QTL clusters, and validated using quantitative real-time (qRT)–PCR.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Carlos A. Avila ◽  
Thiago G. Marconi ◽  
Zenaida Viloria ◽  
Julianna Kurpis ◽  
Sonia Y. Del Rio

Abstract The tomato-potato psyllid (TPP), Bactericera cockerelli, is a vector for the phloem-limited bacterium Candidatus Liberibacter solanacearum (Lso), the causative agent of economically important diseases including tomato vein-greening and potato zebra chip. Here, we screened 11 wild tomato relatives for TPP resistance as potential resources for tomato (Solanum lycopersicum) cultivar development. Six accessions with strong TPP resistance (survival <10%) were identified within S. habrochaites, S. pennelli, S. huaylasense, S. chmielewskii, S. corneliomulleri, and S. galapagense. Two S. pennelli and S. corneliomulleri accessions also showed resistance to Lso. We evaluated recombinant inbred lines (RILs) carrying resistance from S. habrochaites accession LA1777 in the S. lycopersicum background and identified major quantitative trait loci (QTLs) responsible for adult TPP mortality and fecundity in several RILs carrying insertions in different chromosomes, indicating the polygenic nature of these traits. Analysis of a major resistance QTL in RIL LA3952 on chromosome 8 revealed that the presence of Lso is required to increase adult TPP mortality. By contrast, the reduced TPP oviposition trait in LA3952 is independent of Lso. Therefore, resistance traits are available in wild-tomato species, although their complex inheritance and modes of action require further characterisation to optimise their utilisation for tomato improvement.


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