The study was aimed to explore the relationship between the root distribution at different growth angles and the ratooning ability in sugarcane, and to screen the iconic root indexes of strong ratooning in sugarcane. Three sugarcane varieties with different ratooning ability, Yunzhe 08-1609 (A), Yunzhe 05-51 (B), Yuetang 93-159 (C) and strong ratooning sugarcane germplasm Erianthus arundinaceus (D) and Saccharum spontaneum (E), were used as the materials. The root morphology of plant and ratoon crops was continuously measured under the conditions of conventional planting in field. The root biomass and quantity of sugarcane varieties with strong ratoon ability increased continuously during elongation stage of plant crop, and the highest was in the angle range 0°-30° from the vertical direction, followed by that of 30°-45°. The root biomass and numbers in ratoon crop were significantly higher than those in plant crop. The root biomass and numbers in varieties A and B were the highest in the angle range 30°-45°, and that in variety C was the highest in 45°-65°. The root biomass in E. arundinaceus and S. spontaneum was much higher than that in sugarcane varieties in both plant and ratoon crops, the root number in S. spontaneum was the largest while that in E. arundinaceus was close to that in sugarcane varieties. The root biomass of the two wild germplasm materials in plant crop was the highest in the angle range of 0°-30°, while in ratoon crop, the root number distribution in E. arundinaceus was similar at three angle ranges, and of whitch in S. spontaneum was similar in the ranges of 30°-45° and 45°-65°. The root number in variety A was the highest (46.43%) in the angle range of 0°-30° at late elongation stage of plant crop, followed by the range of 30°-45° (42.74%) at late elongation stage of ratoon crop. The root number proportion of S. spontaneum and E. arundinaceus was the highest in the range of 0°-30° at elongation stage of plant crop, followed by the range 45°-65° at elongation stage of ratoon crop. The top five indicators correlated with the ratooning ability were the root surface area, root volume, root length, root fresh weight, and root number within the angle range of 0°-30° to the vertical direction. For evaluating the ratooning ability of sugarcane, it is suggested to refer to the root index in the angle range of 0°-30° from the vertical direction in plant crop, and the root fresh weight could be used as a key index for preliminary screening of the ratooning ability. In addition, if there was no rhizomes, the ratooning ability can be predicted by the ratio of average single root weight in ratoon to that in plant crop.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |