Identification And Evaluation Of Banana Strain ’HD-1’

Banana is one of the superior products with international competitiveness in China, which have a high status in tropical and subtropical fruit trees. At present, the main cultivated banana varieties in China are single, such as Brazil、Williams, etc., lacking of germplasm innovation. Therefore, the primary goals of the banana breeding are still high yield, good quality and strong resistance. In the field survey of banana resources, our team found a potential banana mutant strain (temporarily named as’HD-1’). But its genetic relationship, resistance strength, performance and other aspects are not clear. This test intends to use Simmonds classification and karyotype analysis to determine banana line ’HD-1’kinship; Compare with Brazil, we want to study the abiotic stress resistance and the biological resistance of Fudatium Wilt race4with ’HD-1’seedlings, using artificial environment test methods; Field trials is growing bananas lines ’HD-1’and observing its botany and agronomy shape. Designed to determine the genetic relationships, agronomic traits, resistance, etc. of the strains, provide the basis for new varieties of validation work. The results are as follows:(1) By planting field tests in Hainan Danzhou area showed that pseudostem height of ’HD-1’is165.5cm, dwarf varieties; pseudostem circumference is61.7cm; stems false color is light purple. The angle between the line (the blade tip to the base of the petiole) and the horizontal is about45°, upright; petioles distribution of a small amount of dark brown spots, and the edge of the petiole slot opened outwards. Oval Leaves compact, broad and thick, leaf index is1.95, petiole length is24.6cm; foliage is dark green, dorsal is light green and shiny waxy. Spikes have5opened petals, style slightly curved, stigma have six points, ovary gradients from the quartet or pentagonal prismatic to circular in growth, janus-faced leather, developmental condition of composite petal lobes and free petal topis good; cone ear tightness is closer and larger, ear shank thickness is57cm,9comb/ear, ear length is59.3cm, single spike weight20.8kg; fruit refers to the double Hopson, fruit index is159.7/spike, fruit refers to a length of19.1cm, the fruit is slightly curved finger traits; fruit edible rate is66.3%and soluble solids content is26.0%, soluble sugar content is20.5%, titratable acidity is0.53%, Vit C content is55mg/100g; growth period contain335d. Banana comparison with Brazil, mainly in the banana lines ’HD-1’ dwarf plants, short growth period13days, soluble solids content of up to26.0%, slightly lower than the average ear weight Brazilian banana.(2) According to Simmonds classification description, banana lines ’HD-1’ fake shorter stems, pale purple; their leaves are dark green and compact with small opening degree, their petioles groove edges which do not wrap a false stem are upright red and outward; their bracts with buds scar protrusions are lanceolate and reflexed, reddish-brown exterior, interior red. Points classification standard Simmonds discrimination, banana lines ’HD-1’is the result of scoring21points, ploidy of3×, type AAA.(3) After karyotype analysis, we know that the banana lines ’HD-1’ number of chromosomes is33, karyotype formula is2n=3x=33=2L+3M2+4M1+2S, where chromosome1,2,3are near the centromere of chromosome, the rest are metacentric chromosomes, central point was not found with the body. Longest chromosome to the shortest length ratio is2.476, arm ratio range is1.063-1.846; arm ratio of all chromosomes are less than2, nuclear type classified as "1B", more symmetrical karyotype.(4) Using ISSR molecular markers to analyze the kinship between banana strains ’HD-1’ and18suspected banana varieties. Banana ’HD-1’ has the closest relationship with Pubei dwarf banana and Tianbao dwarf banana, the similarity coefficient is0.81.(5) Through tests under artificial anti-cold, drought and salt environment, banana lines ’HD-1’s physiological and biochemical changes in seedlings showed that:compared with normal temperature control, after three different stress, the relative conductivity and MDA content are significantly increased, but the increase of’HD-1’is lower than Brazil banana; SOD, POD activity banana of lines’HD-1’are significantly greater than the growth in the Brazil banana; their relative water content are significantly decreased, but the banana line ’HD-1’maintains a high level; Brazil’s penetration substance growth rate was significantly lower than ’HD-1’. These results show that when suffering cold, drought stress and salt damage,’HD-1’ shows a stronger defense capability than Brazil bananas. Therefore, banana lines ’HD-1’ bananas have a stronger abiotic stress resistance.(6) The use of root-dip inoculation method of banana seedlings were inoculated with Fusarium Race4species, the results show that the resistance grade of ’HD-1’is3, resistance level is "susceptible"; the resistance grade of Brazil is4, resistance level "high sense". Therefore, banana lines ’HD-1’ banana showed strong resistance capacity to Fusarium wilt than Brazil.