S (PH D THESIS) Involvement of auxin distribution in root nodule development of Lotus japonicus (Graduate School of Agriculture, Laboratory of Plant Gene Expression, RISH, Kyoto University) Kojiro TAKANASHI Legumes (Fabaceae) constitute the third largest plant family with around 700 genera and 20,000 species. Legume plants form root nodules through symbiosis with a soil microbe called rhizobia....

Characterizing plant functional diversity is essential to decipher community assembly rules and ecosystem functioning. Most studies focused on above-ground traits whereas the analysis of root lags far behind. We analyzed structure fine (< 2 mm) diameter distribution at level as an indicator morphological diversity, hypothesized that shape provide insights types exploration strategies. tested th...

The restricted likelihood ratio test, RLRT, for the autoregressive coefficient in autoregressive models has recently been shown to be second order pivotal when the autoregressive coefficient is in the interior of the parameter space and so is very well approximated by the χ1 distribution. In this paper, the non-standard asymptotic distribution of the RLRT for the unit root boundary value is obt...

many fungi cause sugar beet root rot during various stages of the plant growth. among them rhizoctonia spp. induce crown rot, dry rot and violet root rot on sugar beet (whitney and duffos,1986). root rot caused by phytophthora drechsleri has been observed in fields with excessive moisture (habibi,1975). pythium aphanidermatum has been recognized as one of the causal agents of sugar beet, dampin...

this study analyzed the relationship between the vertical distribution of root biomass and soil organic carbon (soc)content in the arid shrub lands of semnan province in iran. three sites were selected based on differences in canopy coverof artemisia sieberi (5%, 10% and 15%). average density of shrubs, root biomass and soc were determined at differentdepths (0-20, 20-40, 40-60, 60-80 cm) in 20...

Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content ...

abstract in order to identify of plant parasitic nematodes of rapeseed in isfahan and fars provinces, 208(96 from esfahan and 112 from fars province) soil and root samples were collected from rapeseed fields during 2005-2007. nematodes were extracted from root and soil , then fixed and transferred to glycerin. the nematodes were mounted on slides and examined by light microscope and identified ...

土壌水分欠損量と土壌水分の静水圧平衡の仮定を用いることにより，根の分布を考慮して蒸散量を推定できるモデルを開発した．このモデルは，改良した神田・日野のモデルを用いて根からの吸水を計算し，Makkinkの式を用いて葉の水分要求を計算する．また，ガンマ分布を導入して，根の鉛直分布を表現している．さらに，入力には気象と土壌のオープンデータのみを必要とする．森林総合研究所竜ノ口山森林理水試験地にモデルを適用して解析を行った結果，遮断蒸発と蒸散をあわせて，概ね10%の誤差で蒸発散量推定を行うことができた．モデルから，土壌水分量の減少によって蒸散が抑制されない場合であっても，根の水分供給能の限界によって蒸散の制約が生じ，蒸散が頭打ちになることが示された．また，根が深層の土壌水分を利用するために，裸地面と比較して，蒸発散の効率が低下しにくいことを，モデルが定量的に表現できることが示された．