اريد التعرف عليك

اريد التعرف عليك

النتائج (الإنجليزية) 1:

I want to know you

النتائج (الإنجليزية) 2:

I want to get to know you

النتائج (الإنجليزية) 3:

Tonnage (T), Simmonds (S) avocado trees, and TxS crosses were evaluated for differences in chlorophyllContent and maximal quantum yield of photosystem II in sun and shade-type leaves. Total chlorophyll content byArea (Chl a+bar) ranged from 984 mg m-2 in TxS240 to 4320 mg m-2 in Simmonds. Chlorophyll A / B ratio (Chl A / b)Ranged from 9.8 to 5.5 in TxS238 and TxS243, respectively. Tonnage and Simmonds had similar Chl A / B with aWide range in values found among the avocado trees tested. Shade leaves contained more Chl a, Chl B and ChlA+bwt than sun leaves. Differences in Chl A / B were insignificant or greater in shade adapted leaves for all treesExcept TxS238; this did not follow the expected sun / shade pattern. A low chlorophyll a / B ratio indicates moreLight harvesting proteins and higher stacking of thylakoids. Chl a+bar indicates Simmonds, Tonnage and to aLesser extent TxS238 had dense packing of chloroplasts in both sun and shade adapted leaves. Shade leaves hadMore efficient Fv / Fm values than those adapted to sun for all varieties except TxS240. Tonnage had the largestRange of total chlorophyll content between shade and sun adapted leaves and likely has the largest geneticVariation in its ability to acclimate to changing light intensities. The range in efficiency of photosystem 11 foundBetween the avocado trees tested indicates a potential for improvements through selective breeding. MoreResearch is needed to evaluate the entire USDA avocado germplasm collection for traits associated withPhotosynthetic efficiency and to determine their heritability.