Detection and evaluation of seed damage of cypress, Cupressus sempervirensL., in Italy

The damage to cypress seed caused by insects and tree pathogens was estimat ed in a plantation of a clone patented for resistance to cypress canker (Ag rimed 1) and in a stand heavily attacked by the canker, which is caused by the fungus Seiridium cardinals. Five seed quality categories were identifie d based on X-ray analysis. Filled seeds were more abundant in the clonal pl antation whereas empty seeds prevailed in the stand. Seed damage by insects , a seed bug (Orsillus maculatus) and a seed chalcid (Megastigmus wachtli), was higher in the stand whereas the brown degeneration of the gametophyte occurred more frequently in seed from the clonal plantation. Cones infected with S. cardinale produced fewer filled seeds and more empty seeds than he althy cones. An incubation experiment conducted with seed from healthy and fungus infected cones allowed to detect the presence of pathogens and to ev aluate the germination capacity of the seed for each of the five seed quali ty categories. In healthy cones the pathogens, mainly S. cardinale and Pest alotiopsis funerea, were associated with seed damage by insects. Seed germi nation occurred almost exclusively for filled seeds. These findings may sup port the suitability of X-ray analysis in the assessment of cypress seed qu ality and emphasize the role of seed insects in disseminating the fungus am ong cypress cones.