*2.2.2 Aspergillosis*

Often, aspergillosis of pomegranates is caused by species of *Aspergillus* belonging to the section *nigri*, also called "black aspergilli." Almost 27 species belong to this section, displaying high inter- and intra-specificity genomic variability; their taxonomy is really

#### **Figure 5.**

*Penicillium s.l. decay. (A) Necrotic lesion covered with blue-greenish sporification. (B) Cracking, (C) wound, and (D) infected stamens [6].*

#### *Pomegranate: Postharvest Fungal Diseases and Control DOI: http://dx.doi.org/10.5772/intechopen.109665*

complicated and not completely solved [58, 59]. Species may be misidentified, and it is not easy evaluating the incidence of each species within the section [59]; furthermore, species identification is relevant especially from a sanitary point of view since some species are potential mycotoxin producers [59]. In general, black aspergilli are well-known as wound pathogens but they could cause internal decay too [6, 60]. *A. niger,* the most spread species within this genus, is recorded in Turkey, Greece, India, Pakistan, and China [61–64], but no evidence of its presence in Italy, where black aspergilli isolated from pomegranate belong to the species *A. tubingensis*, *A. welwitschiae*, *A. uvarum*, and *A. japonicus* [6], being the first identified also in China [65]. *A. niger* and its sister species *A. welwitschiae* are the most hazardous species since they are putative producers of ochratoxin A (OTA) and fumonisins. According to IARC classification, these last are nephrotoxic and hepatotoxic with potential carcinogenic effects on rat and mice; instead, OTA has nephrotoxic and teratogenic, carcinogenic, and immunotoxic properties in rats and possibly in humans [59]. Unfortunately, regulations still do not report limits for mycotoxin amount in fresh pomegranates and their derivatives. Regarding distinctive symptoms, early stage of infection is featured by rind concentric discoloration, from yellow to red-brownish colored (**Figure 6A**-**C**). Internally, pomegranates show a soft brownish-black rot of the arils that may be covered by black powdery sporulation (**Figure 6D**). Black aspergilli cultures appear cottony or velvet-like in texture (**Figure 6E**). Hyphae are septate and hyaline, and mycelium is whitish, but spore development leads to a black appearance; in general, yellow and white shades characterize colony reverse. Characteristic conidiophores are aspergillum-shaped; metulae maintain the phialides and related vesicles. Conidia (2–5 μm in diameter) are arranged in radial chains that give it the characteristic shape. As in the case of *Penicillium s.l.*,

#### **Figure 6.**

*Aspergillus sect. Nigri rot. (A) Early and (B) advanced stages of the disease. (C) Rind cracking of diseased fruit. (D) View of internal decay; significant is the soft texture of the tissues. (E) Front of a PDA plate of* Aspergillus *spp. [6].*

species identification according to macro- and micromorphology is very difficult, requesting molecular confirmation by PCR amplification of a calmodulin portion with CMD5/CMD6 primer pair [48].

#### **2.3 Other fungal diseases**

Among fungi involved in pomegranate diseases, there is *Cytospora* spp., which can cause wood canker, branch dieback, and postharvest fruit rot. Although in Spain has been reported *C. annulata* [32], the most widespread species is *C. punicae*. This latter has been reported in various pomegranate cultivation areas such as United States, South Africa, Greece, Cyprus, and Italy [6, 66–69]. Postharvest fruit decay is identifiable by circular soft lesions of the rind, creamy-brownish colored, and centrally darker; related subcutaneous area shows a yellowish and corky appearance. In culture, colonies are whitish, then become olive green; at maturity, colonies are dark brown and covered by globose pycnidia (375 ± 125 μm). Allantoid, aseptate, and hyaline conidia meanly measure 5 ± 1 × 1.5 ± 0.5 μm. Finally, are occasionally identified fungal pathogens belonging to *Fusarium* genus in Egypt and Tunisia [70–72]; being a mycotoxigenic genus that potentially produces deoxynivalenol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, nivalenol, fusarenon X, T-2 toxin, HT-2 toxin, neosolaniol, diacetoxyscirpenol; zearalenone, fumonisin B1, fumonisin B2, and fusaric acid [73], fusariosis presence needs to be monitored. Also, *Cladosporium* spp. is described as the etiological agent of fruit rots both in Spain and in China [32, 74].
