Sugarcane improvement in Guangxi: Progress and perspectives

This paper reviews the history of replacements of improved sugarcane varieties and their significant contributions to the cane yield and sugar content in the past several decades in Guangxi. Five obvious replacements of the varieties were recorded typically from local initial cultivated species(S. Sinense) varieties Bamboo cane and Rose Bamboo cane to POJ2878, F134, Guitang 11 (GT11) and ROC16 which is dominant at present. Therefore, from 1950s’ to 2003, it had been increased by about 1,000 times in total sugar yield in Guangxi from 0.004 million tons to 5.86 million tons, and by 315% in milling cane yield per unit area which was increased from 26.6 t/ha. to 66.5 ton /ha. or by 6% per year, and by 0.92 % in absolute sucrose % cane during the past five decades. It is considered that the replacements of sugarcane varieties have played an important role to promote the sugar industry in Guangxi. Based on the severe drought and unfertile soil conditions, the breeding targets of high cane yield, high sugar content, strong drought and disease resistance, and strong ratooning ability have been worked out for the sugarcane breeding program. Total 21 varieties have been bred and released to the commercial production since GXSCRI was established in 1956. It would take further about 10 to 12 years to complete the schedule for a successful new improved variety, in which about 5–6 years selecting in the GXSCRI and 5–6 years in regional trial out the GXSCRI. For broadening the germplasm base of sugarcane breeding, hundreds of wild germplasm materials including 5.spontaneum, S. arundinaceum andMiscanthus, were collected from various locations in China, and 150 varieties were introduced from exotic countries during the past decades. Yacheng (YC)71-374, GT11, ROC1, CP65-357, CP72-1210, YC73-512, ROC10 etc. displayed good combining ability as desiring new parents in recent years. Molecular technology has been used as a supplementary tool for sugarcane breeding. The study made in Guangxi showed that sugarcane nitrogen-fixation research had very significant and good prospect. The RSD pathogen was detected by PCR molecular technology. Transformed plants fromS. spontaneum, E. arundinaceus with bar gene have been cultured through gene gun andAgrobacterium mediated transformation.