| New varieties of plants are the object of new plant variety protection. With the development of breeding industry, the protection of new plant variety is becoming more and more important. DUS is the test of distinctness, uniformity and stability of new plants` varieties. DUS test is technical foundation and authorization of the protection of new varieties of scientific basis.Banana(Musa spp.) is one of the most important fruits in the world. Meanwhile, it is an important food crop. Moreover, banana production is threatened by many diseases and cold weather or other harsh conditions. All these problems have bad effects on the productions of banana. The basic way to solve these problems is choosing and planting resistant cultivars. In this study, the tests of DUS and agronomic traits of five clones were carried out using ‘Beidaijiao’ and ‘Nongke1’(Musa spp. AAA) as the control, respectively. Disease resistance was investigated on two clones(HNAJ0301 and HNAJ0325) using ‘Baxijiao’ and ‘Yueyoukang 1’(Musa spp. AAA), highly susceptible and resistant to the Fusarium oxysporum f. sp. cubense(Foc) respectively as the controls. Clone HNAJ0301 was selected as the representative to study the transcript level changes of some genes involved in disease resistance. The main results obtained are showed as follows:1.The main results of DUS test(1) The growth period of all tested clones exceput HNAJ0219 was significant shorter than that of ‘Beidaaijiao’, the control.(2) The length leaf or petiole of five clones was significantly longer than those of the control. Three clones(HNAJ0212, HNAJ0219, HNAJ0301) had significant wider leaves than the control. In addition, the overlap degree of their leaves was also significantly lower than that of the control.(3) The length, thickness and diameter of fruit fingers of clone HNAJ0325 were significantly higher than those of the control. Another clone, HNAJ0219, also showed bigger finger diameter than the control.(4) The ear length and the weight of the bunch of five clones were significantly higher than those of the control.2. Some agronomic traits(1) Some differences were observed between tested banana clones and the control, ‘Nongke No 1’. The water content, edible ratio of tested clones were higher than those of the control while the water content was on the contrary. All five clones except JNAJ0212 showed higher titratable acid. The content of Vc(Vitamin C) of four clones was higher when compared to the control.(2) The disease resistance of banana to Fusarium wilt. The susceptible cultivar has the highest disease index(0.74), while that of the resistant cultivar is the lowest(0.56) 45 d after pathogen inoculation. The disease index of HNAJ0301 and HNAJ0325 was 0.58 and 0.71, respectively.(3) Changes in transcript leves of some genes associated to disease resistanceIn the non-treated control, the levels of Ma PME32 was highest in clone HNAJ0301, followed by the susceptible cultivar and the resistant one. And significant differences could be observed among them. Wounding resulted in an increased level of this gene in the susceptible cultivar while it was inverse for the resistant one and clone HNAJ0301. The level of Ma PME32 in the susceptible cultivar decreased significantly but it kept stable in the resistant one and clone HNAJ0301. In the non-treated control, Ma PECS-2.1 showed significantly higher levels in the resistant cultivar and clone HNAJ0301 than in the susceptible cultivar. Both of wounding and pathogen infection resulted in decreased gene expression. In the non-treated control, there were no differences in the expression of Ma PR-4 among the tested clones and the control. Furthermore, they showed similar trends after both of wounding and pathogen attack, no significant changes after wounding and increased after pathogen attack. |
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