| Seedling quality is the most fundamental factor for seedling survival and growth in vegetation restoration process, while root morphological and physiological characteristics are important indexes to evaluate seedling quality. The seed-base seedlings and ordinary container of Platycladus orientalis were selected as test materials. We measured the root morphological and physiological properties on the 20 th, 40 th, 60 th, 80 th and 100 th day after breeding. The results showed that:(1) The seed-base technique significantly increased root dry weight, total root length, root tips, root surface area, root density, root density and root volume(p<0.05) during the experimental period, but the average diameter was smaller than ordinary container of Platycladus orientalis. Further, the seed-base technique also could significantly improve the root activity, root soluble sugar, root soluble protein and root proline contents(p<0.05).(2)Root morphological properties, such as root dry weight, total root length, specific root length, root tips, root surface area, root density, root density and root volume, had positive correlation with root physiological characteristics, i.e. root activity, root soluble sugar, root soluble protein and root proline for the both seedlings(p<0.05). However, average root diameter of Seed-base technique had no significant relationships with total root length, specific root length, root density and root soluble protein. There were no significant relationships among root density and specific root length of Platycladus orientalis of ordinary container.(3)The stepwise regression analysis indicated that root dry weight and specific root length accounted for 96.0% variations of root activity playing a decisive role for the seed-base seedlings. Total root length played a decisive effect for root soluble sugar, accounted for 97.3% variations. Root dry weight and root volume played decisive effects for root soluble protein, accounted for 86.5% variations. Total root length, root tips and root diameter played decisive effects for root proline, accounted for 98.7% variations. For the ordinary container seedling of Platycladus orientalis, the root physiological characteristics, i.e. root activity and root soluble protein were determined by root dry weight accounting for 83.6% and 90.9% variations. Root soluble sugar were determined by total root length accounting for 84.9% variations. Total root length, root density and root volume played decisive effects for root proline, accounted for 97.9% variations.(4)The principal component analysis suggested that root dry weight, root surface area, root soluble suger and root diameter could be used as important indexes for evaluating the seedling quality of the seed-base seedling of Platycladus orientalis. While the seedling quality of the container seedling of Platycladus orientalis was determined by root tips, total root length, root proline and root diameter. |
