based on that image, it seems Penicillium sp., but notice and care to days of growth duration, dis-infestation before culturing and so on , because some Aspergillus spp. and Trichoderma spp. may growth and developed as well as that image. Plz make a microscopic slide and share a new microscopic or stereoscopic image.
It's probably a Penicillium and it's probably from your apple, but I always make multiple isolations to make sure I'm not picking up a contaminant, either from the surface of the fruit or from my own lab.
If isolations was done from rotted tissue, it could be P. expansum, which is particularly reported as a postharvest pathogen of apples. You can get a confirmation of this hypothesis by comparing cultural and morphological features with the description provided by Frisvad et al. in 'Polyphasic taxonomy of Penicillium subgenus Penicillium. A guide to identification of food and air-borne terverticillate Penicillia and their mycotoxins', available at RG.
We have isolated Aspergillus, Penicillium, Alternaria, Fusarium, Mucor etc. from rotten apples on Pal sunflower seed medium and APRM agar and studied the morphology of isolates in PHOL and Narayan stain.
In order to identify the fungal isolate to genus level, the simplest way is to study macroscopic and microscopic characteristic.You can easily perform microscopic morphology of the fungal isolate from your plate in PHOL (Pal, Hasegawa, Ono, Lee) stain or Narayan stain which are developed by us in 1990 and 1998, respectively. You may please take the help of some books on Mycology for morphological studies. I have also authored one book entitled" Veterinary and Medical Mycology" which is published by Indian Council of Agricultural Research,New Delhi,India. You can easily download our papers on Pal sunflower seed medium, APRM agar, PHOL stain and Narayan stain from Research Gate or Academia. Our media and stains are cheaper than other media and stains used in Microbiology and Public Health Laboratories. Recently, molecular tools are also employed to identify the fungal isolate. It all depends on the facilities available in your laboratory. Good luck, Prof.Dr.Mahendra Pal Founder Director of Narayan Consultancy on Veterinary Public Health