کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4555691 1329274 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Apical diameter and branching density affect lateral root elongation rates in banana
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک بوم شناسی، تکامل، رفتار و سامانه شناسی
پیش نمایش صفحه اول مقاله
Apical diameter and branching density affect lateral root elongation rates in banana
چکیده انگلیسی

Thick roots elongate faster than thinner ones. However, within one species, the growth achieved by roots of a given diameter can be very variable, and root diameter can only be considered as a determinant of root potential elongation rate. As root elongation is highly correlated to carbon availability, it can be hypothesized that local competition for resources, expressed as the number of lateral roots per unit length (i.e. the branching density), modulates root elongation. Using novel methods in field conditions, we have estimated apical diameters, elongation rates and growth durations of nearly 3500 banana lateral roots, in a field experiment with high radiations and a shaded glasshouse experiment with low radiations. Apical diameters and branching densities were lower in the experiment with low radiation, but elongation rates were higher. In both experiments, mean elongation rates of first-order laterals and thick second-order laterals were negatively correlated with bearing root branching densities. It is hypothesized that, even though apical diameters were lower, low branching densities in the shaded glasshouse allowed enhanced lateral root elongation. In both experiments, second-order laterals elongated more slowly than first-order laterals of similar diameter. A specific effect of root order, independent of branching density and apical diameter, contributed to explain these slow second-order lateral elongation rates. Most lateral roots elongated between 9 and 21 days and growth duration was mainly correlated with root diameter.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Environmental and Experimental Botany - Volume 59, Issue 3, April 2007, Pages 243–251
نویسندگان
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