Studies On The Physiological And Biochemical Characteristics During Pod-development And Gene Clone Which Related With Pod-development In Oilseed Rape (Brassica Napus L.)

Oilseed rape (Brassica napus L.) is one of the most important oil crops in China. As a cultivable crop, pod shattering during pod maturity is not only a serious impact on the seed yield and quality but also affects the mechanized harvesting. It has been reported that 20% of harvest were lost as a result of pod dehiscence in maturity and the losses up to 50% were estimated in seasons when adverse weather conditions delayed harvesting. In this study, the physiological and biochemical characteristics had been studied during the pod development in rapeseed(Brassica napus L.). The morphological characteristics and anatomical features both wildtype and mutant oilseed rape pod had also been studied and clarified the anatomical mechanism of pod shattering in oilseed rape; the gene which related to pod development in oilseed rape nad been cloned using Degenerated-primer PCR method. This study was provided a foundamental basis for pod-shattering resistance breeding.1. This experiment was dealt with the physiological and biochemical characteristics changes during pod growth and development in oilseed rape.The cultivar was used to evaluate the moisture content, SOD enzyme activity, MDA content, POD enzyme activity and PG enzyme activity during pod development .The results showed : The moisture content were no significant changes during pod growth and development; the SOD enzyme activity was risen up with the pod growth and development; but the POD enzyme activity was opposite; the MDA content was declined first and then enhanced with pod growth and development. The PG enzyme first enhanced and then declined after that began to enhance to top.2,Pod shattering in rapeseed (Brassica napus L.) is damage for mechanical harvesting and causes seed loss. A pod dehiscence mutant was identified, preliminary observation had been carried out using morphological and anatomical method in order to identifying and cloning the pod development gene. The results showed that pod valve elongated more slowly than wild type after pollination. The pod length of mutant (1.99 cm) was less than that of wild type (5.18 cm). The seeds of the mutant were clustered in the valve, while the valve had no enough space for seed growth because of its elongation was much slowly, so valves were torn and seeds disclose in the air. The plant height and cauline leaves area of mutant were less than that of wild type. The ultra-structure of pod showed that there was no clearly valve-margin development in the mutant under optical lens and scanning electron microscopy. The number of vascular bundle was different between mutant and wild type. The number of valve cell in the mutant was more than that of wild type. It had 70 cells within 0.022 mm~2 vision in the mutant valve, however only 19 cells in wild type within the same vision. This mutant in this study was similar with fruitfull mutant in Arabidopsis thaliana.3,The model plant, Arabidopsis thaliana, is the same family with rapeseed and has a similar fruit structure and dehiscence mechanism. An intricate process which is related with the fruit development and dehiscence had been cleard in Arabidopsis thaliana. Based on the sequence of FUL gene in Arabidopsis, The degenerated Primer PCR method was used to clone genes which related with the Brassica napus pod development.We designed four pairs of degenerate primers according to cDNA sequences of the ful gene, the specific bands had been amplified by PCR. The specific band were transformed to the T-vector and sequenced. The gene function were be cleared in the future using Agrobacterium-mediated transformation method.