Comparison of Root System Development in Two Rice Cultivars During Stress Recovery from Drought and the Plant Traits for Drought Resistance

Summary

A greenhouse experiment was conducted to compare root system development of two upland rice cultivars, IRAT 13 and Senshou, during recovery from drought stress and to identify the plant traits that confer drought resistance. From 62 days after sowing (62 DAS), drought stress was given for 6 d followed by rewatering for 14 d. Root length density (RLD) and root diameter (thickness) were measured at the end of the stress and rewatering periods. Control plants were well-watered throughout the study. Gultivar IRAT 13 had thicker roots and higher relative RLD (ratio of RLD in drought-stressed plants to that in control plants) than under drought stress, and significantly higher root growth recovery after rewatering cultivar Senshou. Related plant traits such as evapotranspiration (ET), leaf and stem dry weights and weight of senescent leaves (dead leaves) in IRAT 13 were significantly more favorable for drought resistance compared to Senshou.     

不同基因型玉米自交系苗期干旱-复水的生理响应机制

采用称重控水法模拟干旱胁迫,设对照和胁迫两个处理,在3叶期对24个玉米自交系叶片相对含水量(RWC)、游离脯氨酸(Pro)等生理指标进行测定,研究玉米的抗旱机理及复水补偿效应机制。结果表明,干旱胁迫下玉米叶片相对含水量、叶绿素荧光参数(F_v/F_m)和叶绿素含量(Chl)与对照相比显著下降,游离脯氨酸(Pro)、超氧化物歧化酶(SOD)和氧化物酶(POD)明显上升,复水后不同基因型自交系各生理指标表现出不同程度的补偿效应。利用隶属函数法将D17982、郑H71、PH4CV、昌7-2和L269等14份自交系归为抗旱性较强的自交系,PH4CV、HCL645、D17982、郑7314、郑H71和郑9712这6份自交系归为复水恢复能力强的自交系。     

Genotypic Variation in Response of Rainfed Lowland Rice to Prolonged Drought and Rewatering

Abstract

Duration of the drought period is important for plant response during drought and after rewatering. We hypothesized that, if drought duration is extended, (1) high seedling vigor and rapid development of a deep root system will not be advantageous, and (2) osmotic adjustment will be more important. Six diverse rice (Oryza sativa L.) genotypes were selected from rainfed lowland germplasms to examine the development of a deep root system and osmotic adjustment, and their relationship with biomass production during drought and after rewatering, under two different drought durations (shorter and prolonged) in the greenhouse. NSG19 and KDML105 had greater seedling vigor (larger seedling biomass), developed a deep root system earlier in response to drought, extracted soil water more quickly, and their pre-dawn leaf water potential declined more rapidly during the prolonged drought period. These two genotypes showed superior drought recovery even after a prolonged drought period in which they suffered a greater reduction in transpiration, water use efficiency, and biomass production. The superior recovery ability was associated with larger plant size by the end of the drought period rather than with plant water status during drought, such as osmotic adjustment or leaf water potential. Osmotic adjustment was greater during prolonged drought periods (ca. 0.7 MPa) than during shorter drought periods (ca. 0.5 MPa), and lower osmotic adjustment was mostly associated with a higher leaf water potential. Genotypic variation in osmotic adjustment was observed, but there was no clear relationship between osmotic adjustment and biomass production during drought periods. These patterns of response of rice seedlings to drought and rewatering in the greenhouse should help to explain the patterns of adaptation of rainfed lowland rice in the field. Selection for drought recovery ability should be an advantageous strategy for early season drought.     

Photosynthetic Recovery of a Perennial Grass Leymus chinensis after Different Periods of Soil Drought

Abstract

The effects of rewatering after different periods of soil drought stress on the photosynthetic capacity of Leymus chinensis in pots were investigated. The plants were subjected to short-term (10-d), moderate-term (20-day) and long-term (30-d) drought each followed by rewatering. Control plants were well watered during the experimental periods. The long-term water stress without rewatering decreased the chlorophyll content, Chl a/b ratio, carbonic anhydrase (CA) activity, net photosynthetic rate (A), and leaf area compared with the control. Rewatering increased the ratio of Chl a/b, CA activity and A, but decreased the leaf area and ion leakage from the cut leaf pieces. The long-term water stress without rewatering reduced the maximal efficiency of PSII (F_v/F_m), the actual quantum yield (Φ_p), and photochemical quenching (q_p), but these values were increased by rewatering to more than the control level, though non-photochemical quenching (q_N) was decreased as compared with the control. This implied that long-term drought aggravated PSII, but rewatering improved it. The net CO₂-exchange rate showed similar diurnal changes in all treatments, but the rate in the morning was lower in long-term drought (before rewatering) than in the other treatments. These results suggest the photosynthesis of Leymus chinensis may be well adapted to episodical soil drought.     

Plant growth and survival of five introduced and two native/naturalized perennial grass genotypes exposed to two defoliation managements in arid Argentina

The field performance of the native Pappophorum vaginatum, the naturalized Eragrostis curvula and various cultivars of the introduced Achnatherum hymenoides and Leymus cinereus was evaluated as potential forage resources in rangelands of arid Argentina during the warm seasons of 2007/2008 and 2008/2009. Plants of these grass species, obtained from seeds, were transplanted to the field in 2006, when they were 1 year old. During the study years, there were two defoliation managements: plants of all study genotypes either remained undefoliated (controls) or were defoliated twice a year during spring at 5 cm stubble height. Despite tiller number being lower (P < 0·05) on defoliated than on undefoliated plants, and total leaf length per unit basal area being similar (P > 0·05) between defoliation managements by mid‐spring, there were no differences (P > 0·05) in dry weight production between defoliated and undefoliated plants in all genotypes at the end of the second growing season. Plants of one or more of the introduced genotypes showed a similar (P > 0·05) or greater (P < 0·05), but not lower, tiller number per plant and per square centimetre, daughter tiller production, total leaf length and dry weight production per unit basal area than the native species at the end of the first and/or second growing seasons. These morphological variables were similar (P > 0·05) or greater (P < 0·05) in the native than in the naturalized genotype. Plant survival, however, was lower (P < 0·05, overall mean = 20%) in the introduced than in the native (>70%) or naturalized (>39%) genotypes at the end of the first or second growing seasons.     

水分胁迫及复水对玉米光合速率及可溶性糖的影响

采用聚乙二醇(PEG-6000)模拟不同程度的干旱胁迫,研究了不同水分胁迫处理及复水对玉米光合速率和叶片可溶性糖浓度的影响。结果表明,水分胁迫使净光合速率(Pn)下降,叶片可溶性糖浓度升高,且与胁迫程度呈正相关。复水后,轻度胁迫处理的玉米光合速率恢复较快并超过对照,可溶性糖浓度降低但仍然高于对照;重度胁迫处理的光合速率在复水后较长时间内低于对照,可溶性糖的浓度高于对照及轻度胁迫处理。叶片可溶性糖浓度与光合速率之间具有显著的负相关关系。     

Characterization for industrial purposes of the fibre anatomy of perennial ryegrass and tall fescue stem and leaf at three stages in the primary growth

Characterization of grass fibre is important in assessing its potential for industrial fibre applications. Stem and leaf sections were sampled from triplicate field plots of two grass species, perennial ryegrass (PRG) and tall fescue at three dates (monthly from 12 May) in the primary growth, and were used to (a) isolate individual fibre cells and (b) prepare transverse sections. Microscopy and image analysis software were used to determine the length and width of individual fibre cells and the proportion of lignified fibre in stem and leaf transverse sections. The length and width of individual fibre cells were greater (P < 0·001) in stem than in leaf sections, while individual fibre cell length was greater (P < 0·01) for tall fescue than PRG. Harvest date and grass species had little effect (P > 0·05) on the proportion of lignified fibre in the transverse‐sectional area. However, there was a greater (P < 0·001) proportion of lignified fibre in the transverse‐sectional area of grass stems than leaves, with tall fescue having a greater (P < 0·05) stem and leaf transverse‐sectional area and area of lignified fibre in transverse section than PRG. Tall fescue harvested at a later stage of growth, with higher proportions of stem than leaf tissue, may be more suitable for industrial fibre applications.     

A rapid screening technique for drought resistance in potato (Solanum tuberosum L.)

Summary The reduction in growth in the dark of leaf dises floated over polyethylene glycol 6000 solution of water potential −0.4 MPa, relative to the growth of similar leaf dises floated over water for the same period, varied in the range 10–87% in 28 genotypes. The growth reductions in the genotypes tested were in general agreement with what is known about their drought resistance. Publication No. 906, Central Potato Research Institute, Simla.     

Beziehungen zwischen Stengel- und Knollenzahl bei der Kartoffel in Abhängigkeit von wichtigen Einflußfaktoren. II. Der Einfluß des Jahres

Zusammenfassung In sieben Versuchsjahren beeinflusste die jahrestypische Stengelzahl die Zahl der Knollenanlagen pro Pflanze positiv (r=+0,77^*) und der Knollenanlagen pro Stengel in der Tendenz negativ (r= −0,39). Die signifikanten Jahresunterschiede in der Zahl erntef?higer Knollen (>3 cm) pro Pflanze und pro Stengel wurden in gewissem Grade durch die Zahl der angelegten Knollen (r= −0,53 bzw. +0,63), in st?rkerem Ausma? jedoch durch die jahrestypische Reduktionsrate der Knollen bestimmt (r= −0,72 bzw. −0,91^*). Diese war hoch, wenn ein Wechsel von guter Wasserversorgung w?hrend der Knollenbildung zu Wassermangelsituationen w?hrend der Knollenwachstumsphase erfolgte.

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Summary In seven years of field experiments, there were significant differences in the numbers of stems per plant and the number of harvestable tubers (>3 cm) at maturity, per plant and per stem, averaged for two cultivars and three seed treatments (Table 1). There was only a weakly positive correlation between the typical stem number for each year and the number of harvestable tubers per plant (r= +0.2, Table 2), whilst the correlation with the number of tubers initiated was much closer (r= +0.77^*, Table 2). The negative influence of number of stems on number of tubers per stem is shown byr= −0.39 and −0.47 (Table 2). Identical stem populations in the wet, cold spring of 1987, and the warm, dry season of 1983 initiated fewer tubers per stem than in 1989 with its average temperatures and modest precipitation (Table 1). Tuber set per plant and per stem correlated positively with the number of harvested tubers per plant and per stem (r= +0.53 and +0.63) and accounted for some of the yearly variation. A much stronger effect on the number of harvestable tubers came from the annual reduction of tubers (r= −0.72 and −0.91^*, Table 2). This was high if the availability of water deteriorated in the period of growth succeeding tuber formation (Table 1, Fig. 1). The same applied to the seed treatments planted at different stages of development. Tuber development occurred earlier with chitted seed, often at times when there was an adequate water supply. A large number of tubers were initiated and these were in large part reduced in the short dry spells which followed (Figs 2 and 4). Irrigation programmes must take account of this relationship.

     

Source–sink relations and kernel weight differences in maize temperate hybrids

Maize (Zea mays L.) kernel weight (KW) response to changes in assimilate availability per kernel during grain filling suggests that plants establish an early kernel sink potential that place them to grow close to a saturating assimilate availability condition during late grain-filling, meaning source limitations are common only early in kernel development. As maize reproductive efficiency in kernel set is not constant across different plant growth rates (PGR) around flowering, we used PGR per kernel during this period as an indicator of source availability per kernel. We tested whether PGR per kernel during flowering or during the effective grain-filling period were correlated to genotypic and environmental differences in final KW. Plant growth rate during both periods, KW, kernel growth rate during the effective grain-filling period, total duration of grain filling and kernel number per plant were measured in 12 commercial genotypes differing in KW sown at two sites under full irrigation. As expected from the curvilinear response relating kernel number per plant and PGR around flowering, increased PGRs resulted in higher PGR per kernel around this period (r² = 0.86; p < 0.001). Differences in final KW due to genotypes or environments were significantly explained by the PGR per kernel around flowering (r² = 0.40; p < 0.001), and not by the PGR per kernel during the effective grain-filling period. Genotypes differed in kernel growth rate (p < 0.001) and grain-filling duration (p < 0.001). The former was well explained by PGR per kernel around flowering (r² = 0.66; p < 0.001), but showed no relationship with the PGR per kernel during the effective grain-filling period. Grain-filling duration was partially explained (r² = 0.27; p < 0.01) by the ratio between PGR per kernel during the effective grain-filling period and kernel growth rate, but differences in duration were negligible compared to those observed in the ratio (∼41% versus ∼130%, respectively). Together, these results support the importance of source availability per kernel during early grain filling on the determination of maize potential sink capacity and final KW. Early resource availability per kernel was accurately estimated as PGR per kernel around the period of kernel number determination, which helped explain genotypic and environmental differences in maize final KW as well as in kernel growth rate.     

Evaluation of the SPAD Value in Faba Bean (Vicia fabaL.) Leaves in Relation to Different Fertilizer Applications

Abstract

The correlations of the reading of a portable chlorophyll meter (SPAD-502) with the chlorophyll and N contents of leaves of two faba bean (Vicia fabaL.) cultivars, Japanese (Ryousai-issun) and Egyptian (Cairo 241), were examined. The SPAD readings positively correlated (ρ<0.01) with the chlorophyll contents and the r² values were 0.99 and 1.00 for Ryousai-issun and Cairo 241, respectively. A close linear relationship (ρ0.001) was observed between SPAD reading and total leaf N content at the pod development stage of faba bean plants with r² = 0.88 and 0.99 for Ryousai-issun and Cairo 241, respectively. The SPAD reading was the highest in the 2^nd to 4^th leaves counted from the top (the youngest fully expanded leaves). The changes in leaf chlorophyll content of both cultivars from 3 weeks after transplanting to the ripening stage showed an incomplete “M” type curve. SPAD readings were significant¬ly higher in Ryousai-issun than in Cairo 241 throughout the growth season. Organic fertilizers application improved faba bean plant growth. These results suggest that the SPAD-502 chlorophyll meter can be used to measure chlorophyll and nitrogen contents of faba bean leaves for quick screening faba bean genotypes.     

Morpho-Physiological Response of Oryza glaberrima to Gradual Soil Drying

Soil drought occurrence during dry season has been the main constraint, besides prolonged flooding during rainy season, in increasing cropping intensity and rice productivity in tropical riparian wetland. Use of drought tolerant rice genotype might be a suitable option for overcoming such problem. This study focused on the effects of gradual soil drying during early vegetative growth stage on morphological and physiological traits of five Oryza glaberrima genotypes, namely RAM12, RAM14, RAM59, RAM97 and RAM101, and two Oryza sativa subsp japonica genotypes, i.e. Koshihikari and Minamihatamochi. The plants were subjected to 6 d of gradual soil drying condition from 15 days after transplanting (DAT) to 20 DAT, and were allowed to recover until 22 DAT. Gradual soil drying reduced plant growth as indicated by dry mass accumulation. Drought reduced stomatal conductance and increased leaf rolling score of all the genotypes. All the genotypes showed comparable response on stomatal conductance, but O. glaberrima genotypes performed higher in leaf rolling recovery. Meanwhile, O. sativa genotypes decreased total leaf area and specific leaf area, but increased specific leaf weight in order to avoid further damages due to drought stress. Drought tolerance mechanisms in RAM101, RAM12, RAM59 and RAM14 were associated with leaf morpho-physiological responses, root traits and dry biomass accumulation.     

Irrigation effects on elephant grass morphology,and its genotype-dependent responses

This study hypothesised that different elephant grass genotypes respond differently in terms of their morphological development to irrigation. The objective of this study was to evaluate how water availability could affect the morphological development of different genotypes of elephant grass. The treatments consisted of four genotypes of elephant grass [Cenchrus purpureus (Schumach.) Morrone], managed under irrigation or not, during a two-year field trial. The experiment was arranged in a randomised block design in a split-plot, with four replicates per treatment (n = 4). Between the genotypes, two of them were classified as tall-sized (IRI 381 and Elephant B), and two as dwarfs (Taiwan A-146 2.37 and Mott). A three-way interaction between season, irrigation, and genotype affected the variables plant height, stem diameter, number of dead tillers, light interception (LI), and leaf area index (LAI) (p < .05). The morphological development of all genotypes was negatively impacted by the dry season. All genotypes grew taller during the rainy season (p < .05) and had a greater light interception (62%–80%) compared to the dry period (28%–59%). The genotype Mott, showed comparable LI and LAI to the tall-sized genotypes, whilst Taiwan A-146 2.37 was characterized by the lowest values, despite being the genotype with the greatest tiller density (60 tillers m⁻²) (p < .05). The use of irrigation mitigated the negative effects of the dry season on the plants, however, the type and size (tall vs. dwarf) of the elephant grass genotypes defined the extent of the responses to the use of the irrigation during the dry period.     

Children Consuming Cassava as a Staple Food are at Risk for Inadequate Zinc, Iron, and Vitamin A Intake

Cassava contains little zinc, iron, and β-carotene, yet it is the primary staple crop of over 250 million Africans. This study used a 24-hour dietary recall to test the hypothesis that among healthy children aged 2–5 years in Nigeria and Kenya, cassava’s contribution to the childrens’ daily diets is inversely related to intakes of zinc, iron, and vitamin A. Dietary and demographic data and anthropometric measurements were collected from 449 Kenyan and 793 Nigerian children. Among Kenyan children 89% derived at least 25% of their dietary energy from cassava, while among the Nigerian children 31% derived at least 25% of energy from cassava. Spearman’s correlation coefficient between the fraction of dietary energy obtained from cassava and vitamin A intake was r = −0.15, P < 0.0001, zinc intake was r = −0.11, P < 0.0001 and iron intake was r = −0.36, P < 0.0001. In Kenya, 59% of children consumed adequate vitamin A, 22% iron, and 31% zinc. In Nigeria, 17% of children had adequate intake of vitamin A, 57% iron, and 41% zinc. Consumption of cassava is a risk factor for inadequate vitamin A, zinc and/or iron intake.     

Screening soybean (grain and vegetable) genotypes for nutrients and anti-nutritional factors

Fifty six genotypes of grain-type soybean and 17 genotypes of vegetable-type soybean collections were analyzed for protein and oil content, trypsin inhibitor, and lipoxygenase activities. The protein and oil content ranged from 36.9 to 47.9% and from 13.3 to 23.0% for different accessions in grain- and vegetable-type soybeans, respectively. Trypsin inhibitor and lipoxygenase activities ranged from 22.0 to 47.0 trypsin inhibitor units/mg meal and from 482 to 6265 lipoxygenase units/min/mg meal for grain- and vegetable-type soybeans, respectively. Significant correlations (r=–0.62 and –0.52,P<0.05) were found between protein and oil, and between protein and trypsin inhibitor. A significant positive correlation (r=0.42,P<0.05) was also calculated for oil and lipoxygenase activity. Several genotypes of soybean and vegetable soybean (plant introductions 423905, 417330, 417223, 171451, 200506, 200523, 417124, 227687, 203402, 445842, 203399, 423852, 416771, FC31927, Avoyelles, and Sooty) showed good nutritional potential and may be useful in a breeding program to improve the nutritional quality of soybean. Screening for essential amino acids, fatty acids, and trace minerals for selected genotypes is underway.     

A model explaining genotypic and environmental variation in leaf area development of rice based on biomass growth and leaf N accumulation

Leaf area index (LAI) is one of the major determinants of crop photosynthesis. The objectives of this study were to clarify the relationship between LAI development and crop growth in diverse rice genotypes grown under widely different climate conditions and to develop a model explaining genotypic and environmental variation in LAI dynamics based on environmental and plant factors. Cross-locational experiments were conducted with nine different rice genotypes at eight locations in Asia covering a wide climate range under irrigated conditions with sufficient nitrogen application. The LAI observed at the heading stage ranged from 0.85 to 8.77 among the genotypes grown at the eight locations. A fairly stable allometric relationship was observed between LAI development and above-ground biomass growth during the period from transplanting to 2 weeks before heading over all the genotypes, sites and years (r = 0.91). The allometric relationship was, however, under the influence of leaf nitrogen content per unit leaf area (LNC, g m⁻² leaf) and air temperature. On the basis of these results, we modeled the LAI development as a function of relative crop growth rate (RGR), LNC and air temperature. The rate of LAI decrease associated with leaf senescence was also described as a function of LNC.     

A process model for explaining genotypic and environmental variation in growth and yield of rice based on measured plant N accumulation

The objective of this study was to develop a mechanistic model for simulating the genotypic and environmental variation in rice growth and yield based on measured plant N accumulation. The model calibrations and evaluations were conducted for rice growth and yield data obtained from a cross-locational experiment on 9 genotypes at 7 climatically different locations in Asia. The rough dry grain yield measured in the experiment ranged from 71 to 1044 g m⁻² over the genotypes and locations. An entire process model was developed by integrating sub-models for simulating the processes of leaf area index development, partitioning of nitrogen within plant organs, vegetative biomass growth, spikelet number determination, and yield. The entire process model considered down-regulation of photosynthesis caused by limited capacity for end-product utilization in growing sink organs by representing canopy photosynthetic rate as a function of sugar content per unit leaf nitrogen content. The model well explained the observed genotypic and environmental variation in the dynamics of above-ground biomass growth (for validation dataset, R² = 95), leaf area index development (R² = 0.82) and leaf N content (R² = 0.85), and spikelet number per unit area (R² = 0.67) and rough grain yield (R² = 0.66), simultaneously. The model calibrations for each sub-model and the entire process model against observed data identified 10 genotype-specific model parameters as important traits for determining genotypic differences in the growth attributes. Out of the 10 parameters, 5 were related to the processes of phenological development and spikelet sterility, considered to be major determinants of genotypic adaptability to climate. The other 5 parameters of stomatal conductance, radiation extinction coefficient, nitrogen use efficiency in spikelet differentiation, critical leaf N causing senescence, and potential single grain mass had significant influence on the yield potential of genotypes under given climate conditions.     

Effect of nitrogen source on growth and morphogenesis of three micropropagated potato cultivars

Summary Different nitrogen sources (NO₃ ⁻, NH₄ ⁺, glutamic acid and their combinations) influenced the growth and morphogenic responses (node number, shoot length, and stem, leaf and root dry weight) of three micropropagated potato cultivars (Spunta, Kennebec, Huinkul). Addition of reduced nitrogen (NH₄ ⁺ or glutamic acid) in a nitrate medium increased shoot length and leaf number. The large increase in growth in plants fed with NO₃ ⁻, NH₄ ⁺ could be explained by higher organic nitrogen content and enhanced dry matter partition to the shoot. This suggests that reduced nitrogen source is required, at least as a supplement to NO₃ ⁻, to enhance N assimilation and growth.     

Carpel weight, grain length and stabilized grain water content are physiological drivers of grain weight determination of wheat

Among the yield components, grain weight is considered a conservative trait whose determination is still beyond our complete understanding. Crop physiology uses a whole approach to study this complex trait, which can provide helpful information to plant breeders and molecular biologists. This study emphasizes the understanding of pre- and post-anthesis determinants of final grain weight. A field experiment was carried out in two growing seasons evaluating two wheat cultivars contrasting in grain weight potential. Carpel weight at pollination, grain dimensions, grain water, dry matter and volume dynamics were assessed. Among grain dimensions, grain length was the trait, which explained final grain weight (r² = 0.78; P < 0.01 and r² = 0.94; P < 0.001 for the 1st and 2nd season, respectively) and it was the first trait to stabilize after anthesis. Water content of grains stabilized little later and also showed a strong association with final grain weight (r² = 0.93; P < 0.01 and r² = 0.98; P < 0.01 for the 1st and 2nd season respectively). Most importantly, carpel weight at pollination showed a positive and linear association with final grain weight (r² = 0.79, P < 0.01 and r² = 0.86 P < 0.01 for the 1st and 2nd season, respectively) irrespective of the cultivar and grain position. In addition, positive associations were also found between grain volume, water content, grain length, and carpel weight at pollination. Therefore, the associations between pre- and post-anthesis traits found in this study support the hypothesis that grain weight is determined before anthesis and fruit tissues (i.e., pericarp in cereals and sunflower) set an upper limit to grain weight.     

Effects of Untreated and Thermally Treated Lupin Protein on Plasma and Liver Lipids of Rats Fed a Hypercholesterolemic High Fat or High Carbohydrate Diet

Lupin protein is capable of reducing plasma lipids in hypercholesterolemic man and animals. Whether lipid-lowering properties of lupin protein will be influenced by thermal treatment or by other nutrients has not been elucidated. In a two-factorial study, rats were fed hypercholesterolemic diets based on high amounts of carbohydrates (HC) or fat (HF), which contained either (20.4% of energy) untreated or thermally treated lupin protein (steam: 120 °C, 30 min) or casein as control protein. Lupin protein lowered plasma lipid concentrations in rats fed the HF diet but not in those fed the HC diet (P < 0.05). Among rats fed the HF diet, plasma and VLDL triglyceride concentrations were lower in rats fed thermally treated (−46% and −44%, P < 0.05) and untreated lupin protein (−47% and −46%, P < 0.05) than in those fed casein; whereas liver triglycerides were reduced only in rats fed untreated lupin protein (P < 0.05). Compared to casein, untreated lupin protein had slightly stronger cholesterol-lowering effects in plasma, LDL and HDL (−34%, −37%, −35%; P < 0.05) than thermally treated lupin protein (−23%, −29%, −31%, P < 0.10). In conclusion, the lipid-lowering effect of lupin protein strongly depends on composition of the basal diet, and thermal treatment is accompanied by a slight reduction of its hypocholesterolemic properties.