Abstract Drought is the most common abiotic stress limiting chickpea production in the world. Ninety percent of the worlds chickpea is produced in areas relying upon conserved, receding soil moisture, therefore, crop productivity is largely dependent on efficient utilization of available soil moisture. Because of the variability in drought pattern from year to year, trait based selection could have an advantage over selection on the basis of grain yield alone. Trait based breeding, however, requires trait dissection into components. Successful marker identification would facilitate integration of MAS procedures in breeding programs enabling the pyramiding of favourable alleles.<p> The genetic map produced in this study was based on a population of recombinant inbred lines of a cross of ILC 588 x ILC 3279 containing 52 SSR markers spanned 335 cM of the chickpea genome at an average density of 6.4 cM. A total of 13 genomic regions were shown to be associated with drought tolerance traits. Some of these genomic regions showed pleiotropic effect on multiple traits. This was also supported by the analysis of phenotypic data where these traits were found to be correlated. For example, early flowering and maturity had a strong association with high grain yield. High grain yield was also associated with better portioning ability between biomass and grain yield, i.e. harvest index. Drought tolerance score (DTS) was associated with various important traits including biomass, early flowering, early maturity.<p> This study also concluded that chickpea genotypes differed in terms of root length, root length density, root weight density and root length to weight ratio at every 20 cm soil layer up to 100 cm depth in response to water deficits. Consideration of an efficient root system vs. a larger root system is also important, since in this research, large root systems were offset by low harvest index, presumably due to the lack of assimilate available for grain growth. A restricted root system is important in environments like Western Canada, where crop growth termination is usually required prior to fall frost. This study also reported significant associations of stomatal conductance (gs) with each of HI, grain yield under drought, drought susceptibility index and drought tolerance score (DTS). Stomatal conductance can also be used to assess plant stress due to drought. Values of gs less than 250 mmol m-2s-1 during flowering indicated drought stress under greenhouse conditions. A higher degree of plant stress due to drought was shown by increased stomatal closure at midday (gs <150 mmol m-2s-1). The study of 157 RILs under natural drought stress during 2005-07 revealed that the 17 RILs which had high grain yield under drought (Group A), also tended to have higher gs than the 42 RILs that had lower grain yield (Group B). Group A had mean gs values of 390 mmol m-2s-1 during the week before flowering, while Group B had mean gs value of 330 mmol m-2s-1. Stomatal conductance increased at flowering and then sharply decreased later in the reproductive period, particularly in Group B. These findings were also supported by canopy temperature differential measurements as Group A was also able to maintain lower canopy temperature than Group B, indicating the ability of these plants to maintain adequate transpiration and a cooler canopy under drought stress. This research indicated that gs and canopy temperature can be used to assess chickpea drought stress and to screen drought tolerant genotypes. This study identified a QTL on LG7 for gs, QTLs on LG1, LG3 and LG6 associated with canopy temperature differential, as well as QTLs associated with grain yield under drought, HI, DTS, days to flower, days to maturity, reproductive period and plant height. These QTLs identified for traits related to higher chickpea productivity under drought stress could have important implications for accelerating the process of pyramiding of favourable genes into adapted genotypes and on future marker-assisted breeding for drought prone areas.

Research was conducted to determine individual suitability of native and Canadian-bred selected plants in terms of growth and survivability for local extensive green roofs. The experiment was single-factor (species) with 12 levels (two Sedum spp. [controls]; 10 Canadian-bred or native plant species) in a randomized complete block design with three blocks. Variables measured were percent survival and cover, height, fresh and dry weights, stomatal conductance, transpiration, photosynthetic rate, soil temperature, soil moisture, and reflectance. Artemisia stelleriana contributed more to cooling through transpiration than Sedum floriferum, and maintained similar soil moisture to Sedum acre. Lotus corniculatus was similar to the controls in photosynthetic rate and had higher reflectance than Sedum acre in July. With high biomass and photosynthetic rates, Aster novi-belgii may contribute more to carbon sequestration and insulation than the controls. Artemisia stelleriana , Lotus corniculatus, and Aster novi-belgii are suitable species for extensive green roofs in northern Nova Scotia.

主催：JST/CREST，Vrije University, ALTERRA, IBPC

No description available.

Thesis (Ph. D.)--Miami University, Dept. of Botany, 2008. / Title from second page of PDF document. Includes bibliographical references (p. 115-131).

Stomatal conductance and mesophyll conductance for CO2 transport are two key components of diffusive limitations of photosynthesis, since they restrict CO2 flux from the leaf surface to the sub-stomatal cavity and from there to the sites of carboxylation. This thesis summarizes our findings in the field of nature of mesophyll conductance to CO2 transport and its regulation per se and in respect to stomatal conductance.

L'efficience intrinsèque d'utilisation de l'eau (Wi) définit comme le rapport de l'assimilation nette de CO2 (A) sur la conductance stomatique à la vapeur d'eau (gs) est un estimateur au niveau foliaire du compromis fait par la plante entre l'accumulation de biomasse et sa consommation en eau. De nombreuses études ont révélé une forte diversité inter et intra-spécifique de ce trait intégré dans le temps dont l'origine est encore mal connue. Les travaux réalisés sur les variations journalières de A et gs ont jusqu'à maintenant révélé un rôle plus important de la diversité de gs dans la diversité de Wi. Une approche de modélisation inversée a permis de décomposer les variations de gs, observées lors de cinétiques journalières, sous la forme de paramètres décrivant les réponses stomatiques aux différentes variables microclimatiques. Comparé aux modèles décrivant les variations de gs en régime permanent, le développement d'un nouveau modèle dynamique a permis d'ajouter une dimension temporelle essentielle décrivant la réponse temporelle des stomates aux variations microclimatiques. La diversité des réponses temporelles des stomates détectée ne semble pas dépendre de leur densité ou de leur taille. Elle présente toutefois une asymétrie entre l'ouverture et la fermeture des stomates qui participe à la diversité des variations journalières de gs et impacte le bilan hydrique journalier au niveau du plant entier. Ainsi, on peut distinguer deux composantes aux variations journalières de Wi liées à gs : une composante temporelle due à la lente réponse des stomates et une autre composante due aux différences de perception des variations du microclimat / Intrinsic water use efficiency (Wi), defined as the ratio between net CO2 assimilation rate (A) and stomatal conductance to water vapour (gs), is a leaf level estimator of the trade-off between biomass accumulation and water loss at the plant level. A number of studies have shown a strong inter and intra-specific diversity, usually using a time integrated estimator of this trait. However, the origin of this diversity is not yet well known. Up to now, research on the daily variations of Wi have shown a stronger influence of gs on the diversity of Wi as compared to A. An inverse modelling approach has allowed partitioning the variations of gs observed during daily time-courses into parameters, which describe the stomatal responses to different microclimatic variables. Compared to steady-state gs models, the development of a new dynamic model of gs has allowed adding a necessary temporal dimension, which describes the temporal response of stomata to environmental variations. The observed diversity of these temporal stomatal responses was not related to stomatal density or size. The temporal responses of stomata were shown to be asymmetric between opening and closing, which impacts the observed diversity of gs during daily time courses as well as whole plant water relations. Overall these results suggest two components that determine the variations of Wi related to gs during daily time courses: one component due to the temporal response of stomata in itself, and one component which is due to differences in the sensing of microclimate variations

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21805号 / 農博第2318号 / 新制||農||1065(附属図書館) / 学位論文||H31||N5177(農学部図書室) / 京都大学大学院農学研究科農学専攻 / (主査)教授 白岩 立彦, 教授 奥本 裕, 教授 稲村 達也 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Two separate experiments were designed to assess the value of Lacy Buckwheat (Eriogonum corymbosum ) as a low water landscape plant. Low water use landscapes can contribute to water conservation in arid climates. Developing a palette of plants that are both attractive and drought tolerant can promote the acceptance of low water use landscapes as an alternative to the traditional bluegrass landscapes of the Intermountain West. Eriogonum corymbosum is an attractive subshrub species native to low rainfall areas of the Colorado Plateau. A strip plot design containing four repetitions with four randomly assigned plants each of Eriogonum corymbosum , Eriogonum thompsoniaeand the control species Cornus sericea `Kelseyi' was established to determine E.corymbosum tolerance to frequent irrigation. Two water treatments were assigned to the repetitions for each species. One treatment was watered by a drip irrigation system with sixteen liters of water every three days; the other treatment was not watered. Stomatal conductance (Gs) and plant water potential were assessed weekly for each species from June through August for the years 2009 and 2010. In 2009 and 2010 bothEriogonum accessions showed no significant difference with the water treatment/accession interaction. NeitherE. corymbosum accession exhibited differences in stomatal conductance or water potential between the wet and dry treatments for the length of study season over both years.Cornus sericea `Kelseyi' showed less ability to withstand the prolonged dry frequencies. Eriogonum corymbosum has many aesthetic qualities, in addition to being drought tolerant, such as long duration late season blooming of yellow and white flowers, and an appealing hemispherical crown shape. A second study was designed to investigate the morphological diversity of thirteen Eriogonum accessions collected in the state of Utah and established in a common garden. Nineteen different variables made up of both quantitative and qualitative morphological characteristics comprised of leaf, canopy and floral characteristics were selected to compare between and within accessions. These characteristics were observed or measured, then used in a Multidimensional Preference analysis (MDPREF) to facilitate the selection of potential cultivars. The MDPREF is useful in selecting accessions with unique combinations of ornamental characteristics that could have a marketable advantage.

Trunk height, diameter, and stomatal conductance measurements were taken over a three-year time frame on clonal red maple cultivars [Acer rubrum ‘Frank Jr’] on two sites with varying conditions. Physiological and morphological effects on tree growth were measured on both sites in response to Pneumatic Fracturing (PF) and Liquid Injection (LI) treatments. The primary questions asked in study one were: (1) Does stomatal conductance differ among the two sites during mid-summer? and (2) Do height and diameter measures differ among the two sites? In study two, I asked: (1) Do height, diameter and stomatal conductance differ between site modification treatments within each site? Control samples on the Site 2 had significantly more growth than the controls on the Site 1. PF and LI treatments showed significantly more diameter growth on the Site 1 while a significant difference was also seen in stomatal conductance following treatments on Site 1.