Mechanical damage in cotton buds caused by the boll weevil

The boll weevil (Anthonomus grandis Boheman) causes high levels of bud abscission in cotton plants due to feeding or oviposition punctures. It has been reported that abscission is mainly due to enzymes present in the insect's saliva, but mechanical damage could also contribute to square abscission. The objective of this paper was to undertake an analysis of the morphological damages caused by the insect in cotton squares using microscopy. Anthers and ovules are the main target of boll weevil feeding. The process initiates by perforation of young sepal and petal tissues and proceeds with subsequent alimentation on stamen and ovary leading to abscission of floral structures

Genetic diversity estimates for individuals of the <i>Theobroma</i> genus.

<p>Genetic diversity estimates for individuals of the <i>Theobroma</i> genus.</p

Genome size of <i>Theobroma</i> species.

<p>Genome size of <i>Theobroma</i> species.</p

Cytogenetic analysis of the genus <i>Theobroma</i>.

<p>(a-a’) metaphase and caryogram of the <i>T</i>. <i>cacao</i> ssp leicocarpum stained with CMA (yellow) and DAPI⁻ (blue). (b-b’) Metaphase and caryogram of <i>T</i>. <i>cacao</i> cv. Scavina 6. (c) metaphase of <i>T</i>. <i>bicolor</i> stained with CMA⁺/DAPI⁻. (d) diakinesis of <i>T</i>. <i>bicolor</i> showing the 10 pair sofbivalent. (e) prometaphase of <i>T</i>. <i>grandiflorum</i>, bars = 5 μm. Arrows in a, b, c points to the CMA⁺ bands.</p

Accessions used for characterization, transferability of EST-SSR markers, genome size measurement and cytogenetics analyses.

<p>Accessions used for characterization, transferability of EST-SSR markers, genome size measurement and cytogenetics analyses.</p

Genetic distance matrix between the three groups of individuals of the genus <i>Theobroma</i>.

<p>Genetic distance matrix between the three groups of individuals of the genus <i>Theobroma</i>.</p

Histogram of relative nuclear DNA content (genome size).

<p>(A) Nuclear DNA content in <i>T</i>. <i>cacao</i> cv. ICS100. (B) <i>S</i>. <i>lycopersicum</i> cells, included as an internal standard. Nuclei isolated from cocoa leaves were stained with propidium iodide and analyzed by flow cytometry.</p