Sclerotium cepivorum (isolate Sc4) hyphae penetrated the epidermis and hypodermis of onion roots and grew into the cortex. Immediately following penetration only the cells through which S. cepivorum grew were lysed, but subsequently cells were killed and cell walls disintegrated ahead of the infection hyphae. Sclerotium cepivorum produced two polygalacturonases (PG) and two pectinesterases (PE) in culture. These isozymes were also found in infected onion root tissues and another PG and a PE were occasionally detected. Two isozymes of PG and three isozymes of PE diffused ahead of the infection hyphae. The spatial distribution of these enzymes was associated with cell death and cell wall degradation. The epidermis, hypodermis, endodermis and vascular tissues were more resistant to hydrolysis than the cortex, but only the endodermis and cells within it retained nuclei following hydrolysis of the surrounding cortical tissues. The cavity within the root cortex became ®lled with swollen, vacuolate S. cepivorum hyphae.

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Integration is currently the only feasible route towards scalable photonic quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip detection will be critical to such devices. We demonstrate an integrated photonnumber resolving detector, operating in the telecom band at 1550 nm, employing an evanescently coupled design that allows it to be placed at arbitrary locations within a planar circuit. Up to 5 photons are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The detection efficiency is 7.2 ± 0.5 %. The polarization sensitivity of the detector is also demonstrated. Detailed modeling of device designs shows a clear and feasible route to reaching high detection efficiencies.

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