The effect of root pruning on the maturation of loblolly pine (Pinus taeda) plantlets, rooted hypocotyls, and seedlings
1991
Wisniewski, L.A. | Brandon, D.L. | McKeand, S.E. | Amerson, H.V.
Loblolly pine (Pinus taeda L.) tissue culture plantlets, seedlings, and rooted hypocotyls were subjected to three root-pruning treatments (control, half apices pruned, all apices pruned) to determine if pruning could alter the maturation state of the shoots, and if there was a correlative alteration of shoot cytokinin levels. Height, multiple characteristics of shoot morphology correlated with maturation, and root morphology were assessed. In comparisons with control plantlets, pruning significantly decreased plant height in half-pruned and all-pruned plantlets, needle length in all-pruned plantlets, terminal bud length and diameter in half-pruned and all-pruned plantlets, and needle dry weight in half-pruned plantlets. When these shoot morphological characteristics were regressed against height, the half-pruned plantlets appeared more juvenile than controls for both terminal bud length and diameter. All-pruned plantlets did not differ from controls. In comparisons of the three intact plant types, the plantlets were more mature than seedlings and rooted hypocotyls based on assessments of terminal bud length, terminal bud diameter, and needle length. However, in the half-pruned treatment these three characteristics did not differ among plantlets, seedlings, and hypocotyls, showing that they were equivalent for maturation status. Root pruning significantly increased the number of root apices for all plant types but did not increase plantlet or rooted hypocotyl cytokinin levels.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by National Agricultural Library