3D pollination biology using micro-computed tomography and geometric morphometrics in .

Premise: Imaging technologies that capture three-dimensional (3D) variation in floral morphology at micro- and nano-resolutions are increasingly accessible. In herkogamous flowers, such as those of , structural barriers between anthers and stigmas represent bottlenecks that restrict pollinator size and access to reproductive organs. To study the unresolved pollination biology of cacao, we present a novel application of micro-computed tomography (micro-CT) using floral dimensions to quantify pollinator functional size limits.

A Previously Undescribed Polerovirus () Infecting Germplasm.

Cacao L. (Malvaceae) is an economically important crop cultivated in tropical climates for the bean from which chocolate and other products are made (Zarrillo et al., 2018).

Complete genome sequences of three newly discovered cacao mild mosaic virus isolates from Theobroma cacao L. in Brazil and Puerto Rico and evidence for recombination.

To analyze the DNA virome associated with cacao (Theobroma cacao L.) trees showing virus-like symptoms in Brazil (BR) and Puerto Rico (PR) during 2018-2019, total DNA was isolated from symptomatic leaves and subjected to high-throughput Illumina sequencing. The assembled complete badnaviral genome sequences were verified by PCR amplification, cloning, and DNA sequencing.

A Complex of Badnavirus Species Infecting Cacao Reveals Mixed Infections, Extensive Genomic Variability, and Interspecific Recombination.

The incidence of cacao swollen shoot disease (CSSD) in cacao ( L.) has increased in West Africa since ~2000. To investigate the genomic and species diversity of the CSSD-badnaviruses infecting cacao in Côte d'Ivoire and Ghana, symptomatic leaves were subjected to high-throughput sequencing.

The Previously Unidentified, Divergent Badnavirus Species Cacao red vein-banding virus is Associated with Cacao Swollen Shoot Disease in Nigeria.

Cacao swollen shoot disease (CSSD) of was reported in Nigeria in 1944; however, no badnaviral genome sequences have been found associated with the symptomatic trees. In 2017, leaf samples ( = 18) were collected from cacao trees from Osun and Oyo, Nigeria showing foliar symptoms that included red vein-banding and shoot swelling, and variable secondary mosaic, mottling, and fern-like pattern symptoms. Abutting primers designed around previously determined 500-bp intergenic region sequences were used for polymerase chain reaction (PCR) amplification.

The proposed new species, cacao red vein virus, and three previously recognized badnavirus species are associated with cacao swollen shoot disease.

Background: Cacao swollen shoot virus (CSSV), Cacao swollen shoot CD virus (CSSCDV), and Cacao swollen shoot Togo A virus (CSSTAV) cause cacao swollen shoot disease (CSSD) in West Africa. During 2000-2003, leaf and shoot-swelling symptoms and rapid tree death were observed in cacao in Cote d'Ivoire and Ghana. Molecular tests showed positive infection in only ~50-60% of symptomatic trees, suggesting the possible emergence of an unknown badnavirus.

Molecular characterization of previously elusive badnaviruses associated with symptomatic cacao in the New World.

Suspected virus-like symptoms were observed in cacao plants in Trinidad during 1943, and the viruses associated with these symptoms were designated as strains A and B of cacao Trinidad virus (CTV). However, viral etiology has not been demonstrated for either phenotype. Total DNA was isolated from symptomatic cacao leaves exhibiting the CTV A and B phenotypes and subjected to Illumina HiSeq and Sanger DNA sequencing.

Identification of QTL regions and SSR markers associated with resistance to reniform nematode in Gossypium barbadense L. accession GB713.

The identification of molecular markers that are closely linked to gene(s) in Gossypium barbadense L. accession GB713 that confer a high level of resistance to reniform nematode (RN), Rotylenchulus reniformis Linford & Oliveira, would be very useful in cotton breeding programs. Our objectives were to determine the inheritance of RN resistance in the accession GB713, to identify SSR markers linked with RN resistance QTLs, and to map these linked markers to specific chromosomes.

SSR markers closely associated with genes for resistance to root-knot nematode on chromosomes 11 and 14 of Upland cotton.

Molecular markers closely linked to genes that confer a high level of resistance to root-knot nematode (RKN) [Meloidogyne incognita (Kofoid & White) Chitwood] in cotton (Gossypium hirsutum L.) germplasm derived from Auburn 623 RNR would greatly facilitate cotton breeding programs. Our objectives were to identify simple sequence repeat (SSR) markers linked to RKN resistance quantitative trait loci (QTL) and map these markers to specific chromosomes.

Identification and genomic location of a reniform nematode (Rotylenchulus reniformis) resistance locus (Ren ari) introgressed from Gossypium aridum into upland cotton (G. hirsutum).

In this association mapping study, a tri-species hybrid, [Gossypium arboreum x (G. hirsutum x G. aridum)(2)], was crossed with MD51ne (G.

Identification of associations between SSR markers and fiber traits in an exotic germplasm derived from multiple crosses among Gossypium tetraploid species.

Genetic improvement in yield and fiber quality is needed for worldwide cotton production. Identification of molecular markers associated with fiber-related traits can facilitate selection for these traits in breeding. This study was designed to identify associations between SSR markers and fiber traits using an exotic germplasm population, species polycross (SP), derived from multiple crosses among Gossypium tetraploid species.

Effects of chromosome-specific introgression in upland cotton on fiber and agronomic traits.

Interspecific chromosome substitution is among the most powerful means of introgression and steps toward quantitative trait locus (QTL) identification. By reducing the genetic "noise" from other chromosomes, it greatly empowers the detection of genetic effects by specific chromosomes on quantitative traits. Here, we report on such results for 14 cotton lines (CS-B) with specific chromosomes or chromosome arms from G.