Root Growth Pattern of Litchi Air Layering Plants and Its Relation to Shoot Growth

Three 'Nuomici' litchi(Litchi chinensis Sonn.) air layering plants were cultivated in root observation chambers to investigate the root morphology and growth pattern,stem extension growth,and relationships between root and stem growth during 12 months.The results showed that different root types varied greatly in morphology,lateral root system was coarse and vigorous with long life span of 8-10 weeks,dense fine roots could only survive for 2-3 weeks;Two air layering plants had 2 higher root growth peaks and 4 lower peaks,while root and stem growth had an alternate growth pattern during one-year period;One air layering plant had one higher root growth peak and 4 lower peaks,while root and stem growth had a synchronous extension pattern;The ratio of root to shoot of 3 plants ranged about 1.0 that indicated root and aerial part grew at equal mass amount.The increase of new root number rather than continuous extension of old root contributed to the occurrence of growth peak.