ABSTRACT Broccoli is increasingly favored by consumers as it is rich in vitamins and many other bioactive compounds. However, existing large tractor-drawn vegetable harvesting machinery is more suitable for large farmland and farm cultivation patterns. Therefore, this paper develops tracked broccoli harvesting equipment for small farmland and tests the ability to harvest broccoli. The tracked broccoli harvester developed in this paper is capable of traveling on its own in the field, cutting the stalks and transporting the broccoli bulbs. This paper analyses the working process of the cutting device and designs the working parameters. Through the cutting bench experiment, the optimal working parameters of the cutting device were determined as 456 r/min of rotational speed, 8.312 mm of overlap, and 0.255 m/s of pusher speed. In the field test, the broccoli leakage rate was 4.8%, the cutting qualification rate was 81.6%, the transport qualification rate was 95.62%, the damage rate was 3.96%, and the total loss rate was 8.55%. This structural model is an important technical support for broccoli harvesting equipment in China.

The identification of expressed genes involved in sexual precocity of the mitten crab (Eriocheir sinensis) is critical for a better understanding of its reproductive development. To this end, we constructed a cDNA library from the rapid developmental stage of testis of E. sinensis and sequenced 3,388 randomly picked clones. After processing, 2,990 high-quality expressed sequence tags (ESTs) were clustered into 2,415 unigenes including 307 contigs and 2,108 singlets, which were then compared to the NCBI non-redundant (nr) protein and nucleotide (nt) database for annotation with Blastx and Blastn, respectively. After further analysis, 922 unigenes were obtained with concrete annotations and 30 unigenes were found to have functions possibly related to the process of reproduction in male crabs - six transcripts relevant to spermatogenesis (especially Cyclin K and RecA homolog DMC1), two transcripts involved in nuclear protein transformation, two heat-shock protein genes, eleven transcription factor genes (a series of zinc-finger proteins), and nine cytoskeleton protein-related genes. Our results, besides providing valuable information related to crustacean reproduction, can also serve as a base for future studies of reproductive and developmental biology.