Large Pots Research Articles

The effect of growth conditions on the seed size/number trade-off.

BackgroundIf the amount of resources allocated to reproduction (K) is fixed, then an increase in seed mass (S) can only be achieved by a decrease in seed number (n = K/S). Thus, log(n) = log(K)−log(S) producing a slope of −1 when seed mass and number are plotted on log-log axes. However, in comparative studies, empirical support for a slope of −1 is limited and contentious, leading some to question the utility of this concept.Methodology/Principal FindingsFirst, we show that the expected slope depends on whether genotypes and species producing seeds of different mass are expected to reach the same adult size and that this in turn depends partly on the nature of growth. Second, we present experimental results using a population of recombinant inbred lines (RILs) of Arabidopsis thaliana. When these RILs are grown in large pots with plentiful nutrients, they exhibit a trade-off between seed size and number with a slope of −1.68 (±0.18) on log-log axes. This occurs because of genetic correlations between seed mass and adult size so that, under the right growth conditions, lines producing lighter seeds have the genetic potential to produce larger rosettes and hence a greater total mass of seeds. We re-grew lines in small pots (10 and 40 mm diameter) in a nutrient-poor substrate so that final adult size was heavily restricted by pot size.Conclusions/SignificanceUnder our growth conditions, small-seeded lines were unable to produce a greater total mass of seeds. Hence a trade-off emerged between seed mass and seed number with a slope of −1.166±0.319 on log-log axes in 40-mm diameter pots (close to the expected value of −1), although the slope was 0.132±0.263 in 10-mm diameter pots, demonstrating that the nature of the trade-off is sensitive to the growth conditions.

Transpiration efficiency over an annual cycle, leaf gas exchange and wood carbon isotope ratio of three tropical tree species

Variation in transpiration efficiency (TE) and its relationship with the stable carbon isotope ratio of wood was investigated in the saplings of three tropical tree species. Five individuals each of Platymiscium pinnatum (Jacq.) Dugand, Swietenia macrophylla King and Tectona grandis Linn. f. were grown individually in large (760 l) pots over 16 months in the Republic of Panama. Cumulative transpiration was determined by repeatedly weighing the pots with a pallet truck scale. Dry matter production was determined by destructive harvest. The TE, expressed as experiment-long dry matter production divided by cumulative water use, averaged 4.1, 4.3 and 2.9 g dry matter kg(-1) water for P. pinnatum, S. macrophylla and T. grandis, respectively. The TE of T. grandis was significantly lower than that of the other two species. Instantaneous measurements of the ratio of intercellular to ambient CO(2) partial pressures (c(i)/c(a)), taken near the end of the experiment, explained 66% of variation in TE. Stomatal conductance was lower in S. macrophylla than in T. grandis, whereas P. pinnatum had similar stomatal conductance to T. grandis, but with a higher photosynthetic rate. Thus, c(i)/c(a) and TE appeared to vary in response to both stomatal conductance and photosynthetic capacity. Stem-wood delta(13)C varied over a relatively narrow range of just 2.2 per thousand, but still explained 28% of variation in TE. The results suggest that leaf-level processes largely determined variation among the three tropical tree species in whole-plant water-use efficiency integrated over a full annual cycle.

Karyomorphological Studies on Chinese Pot Chrysanthemum Cultivars with Large Inflorescences

In this paper, we reported the karyotypes of 30 Chinese large flowered pot chrysanthemum cultivars, differing with respect to flower type, petal type, and flower colour. The interphase nuclei and prophase chromosomes of all the cultivars are, respectively, of the complex chromocentre and the interstitial type. Somatic chromosome number varies from 49 to 62, mostly falling in the range 51–56 or 58. Most of the cultivars are chromosomal mosaics, with three showing 2n = 6x = 54, and two 2n +1= 6x + 1 = 55. At mitotic metaphase, most of the chromosomes are of the metacentric or submetacentric type, with a small number of acrocentrics and telocentrics. B chromosome (s) are present in about 22% of the entireties. The asymmetry index of the chromosomes ranges between 61 and 66%. The karyotypes can be categorized as reversely symmetrical types “2A” or “2B”.

Effects of Pot Size on Leaf Production and Essential Oil Content and Composition of Eucalyptus citriodora hook. (Lemon-Scented Gum)

The influence of pot size on plant height, stem diameter, dry leaf biomass, essential oil content, and composition of Eucalyptus citriodora was investigated in this experiment. Both the physical and the chemical properties of pot-grown plants were significantly affected by pot size. Plants grown in larger pots were generally taller, had thicker stems and wider canopies, grew more branches, and produced more leaves that were larger than plants grown in smaller pots. The highest essential oil concentrations (∼ 1.2%) were observed in plants grown in 1-liter (20-cm diameter) and 5-liter (11 cm diameter) pots. Essential oil composition was fairly similar for all pot sizes. We conclude that Eucalyptus citriodora can be grown in pots, preferably in 10- or 5-liter pots, and thus provide fresh leaves on a daily basis.

Transgenic barley (Hordeum vulgare L.) expressing the wheat aluminium resistance gene (TaALMT1) shows enhanced phosphorus nutrition and grain production when grown on an acid soil

Barley (Hordeum vulgare L.), genetically modified with the Al(3+) resistance gene of wheat (TaALMT1), was compared with a non-transformed sibling line when grown on an acidic and highly phosphate-fixing ferrosol supplied with a range of phosphorus concentrations. In short-term pot trials (26 days), transgenic barley expressing TaALMT1 (GP-ALMT1) was more efficient than a non-transformed sibling line (GP) at taking up phosphorus on acid soil, but the genotypes did not differ when the soil was limed. Differences in phosphorus uptake efficiency on acid soil could be attributed not only to the differential effects of aluminium toxicity on root growth between the genotypes, but also to differences in phosphorus uptake per unit root length. Although GP-ALMT1 out-performed GP on acid soil, it was still not as efficient at taking up phosphorus as plants grown on limed soil. GP-ALMT1 plants grown in acid soil possessed substantially smaller rhizosheaths than those grown in limed soil, suggesting that root hairs were shorter. This is a probable reason for the lower phosphorus uptake efficiency. When grown to maturity in large pots, GP-ALMT1 plants produced more than twice the grain as GP plants grown on acid soil and 80% of the grain produced by limed controls. Expression of TaALMT1 in barley was not associated with a penalty in either total shoot or grain production in the absence of Al(3+), with both genotypes showing equivalent yields in limed soil. These findings demonstrate that an important crop species can be genetically engineered to successfully increase grain production on an acid soil.

Applying evidence: What’s the next action?

Every fortnight my practice group gathers for an early morning “journal club” where we discuss a paper that we think could change our practice. A large pot of tea, an informal atmosphere, and lively discussions have made the sessions popular. But our interest is not the entertainment of pulling apart papers or curiosity about pathophysiology: our central interest is in clinical practice improvement. As in other journal clubs, we critically appraise the paper, calculate the number needed to treat (NNT), and decide on the clinical bottom line. But most journal clubs end there, assuming that everyone will implement the change. But, as we’ve repeatedly experienced, that assumption is often false.1 So following the traditional evidence-based practice steps, we ask, “So what is the next action?”2 The “next action” can be a variety of things. Sometimes the next action is garnering some additional information through another search, writing to the authors, or writing to a local expert. It doesn’t need to be a whole implementation plan, just the next physical action and who is responsible for it.2 For example, at a recent journal club, we discussed measuring blood pressure in both arms. A useful systematic review3 of blood pressure differences between arms made us …

The Effects of Four Organic Soil Conditioners on Aggregate Stability, Pore Size Distribution, and Respiration Activity in a Sandy Loam Soil

In coarse-textured soils, low water and nutrient holding capacity due to the high number of macropores limits crop growth. To minimize these limitations the application of various soil conditioners (SCs) has been extensively used in recent decades. The objective of this study was to investigate the influences of anionic polyacrylamide (PAM), cattle manure (M), vermicompost (VC), and biological sludge (BS) as organic SCs on mean weight diameter (MWD) of aggregates, water aggregate stability (WAS), pore size distribution (PRSD), and respiration activity (RA) of a sandy loam soil. PAM (0.25 and 0.5 g kg^{-1} of air-dried soil), M (12.5 and 25 g kg^{-1} of air-dried soil), VC (2.5 and 5 g kg^{-1} of air-dried soil), and BS (1.7 and 3.4 g kg^{-1} of air-dried soil) were mixed with soil and uniformly packed into large and small pots, and then incubated in a greenhouse with FC moisture content of 0.7-0.8 and temperature of 22 ± 4 °C for 6 months. Large pots were used for soil sampling in order to measure MWD, WAS, and PRSD at 7, 30, 60, 120, and 180 days. Respiration activity was measured at the same times in small pots. All SCs, irrespective of their concentrations, significantly (P 75 \mum) and increased the number of micropores (< 30 \mum). Both PAM rates significantly (P Keywords: Soil conditioner, mean weight diameter, pore size distribution, soil respiration, water aggregate stability

Design and Development of Biodegradable Sapling Pot with Biodegradable Polymer and Biomass

AbstractProcesses of biodegradable molded products were developed. However, to make commercial products to adapted each purpose is still under going. So, this time, to improve the molded products properties, we tested to blend with PLA (polylactic acid) or PBSA (Poly butylenes succinate adipate) into CGM(Corn gluten meal) based agro by-products ingredient.Molded samples were able to make from all tested material and each sample had each physical properties. Finally, we selected suitable condition for practical field test of Large Sapling Pot for Persimmon saplings. Such application will be addressed in our talk and general situation of biodegradable products by biomass resources in Japan will be also introduced.

Applying evidence: what’s the next action?

Every fortnight my practice group gathers for an early morning “journal club” where we discuss a paper that we think could change our practice. A large pot of tea, an...

Applying evidence: what’s the next action?

Every fortnight my practice group gathers for an early morning “journal club” where we discuss a paper that we think could change our practice. A large pot of tea, an...

Linkage between water stress tolerance and life history type in seedlings of nine chaparral species (Rhamnaceae)

Summary 1. Chaparral shrub species along the southwest coast of North America survive wildfire by three different life history types: non-sprouters ( NS ) are killed by fire and only re-establish through germination of fire-stimulated seeds; facultative sprouters ( FS ) re-establish by a combination of vegetative sprouting and seed germination; and obligate sprouters ( OS ) only re-establish by vegetative sprouting because their seeds do not survive fire. 2. Post-fire seedlings of NS and FS re-establish in open canopy gaps, whereas OS seedlings primarily recruit in deep shade during fire-free intervals. 3. It was hypothesized that these life history differences, compared within the same family, Rhamnaceae, would result in differential seedling resistance to water stress such that NS > FS > OS . 4. Seedlings were grown in large pots in a common garden under treatments of sun, shade, irrigation and water stress. Mortality and physiology of seedlings were monitored for about 1 year. 5. In response to the water stress treatment in full sun, life history types were not different in their dry season predawn water potentials, which were extremely negative (< ‐9 MPa). Water potential of water-stressed shade grown plants were also not different, but were less negative than the sun treatment during the dry season (about ‐6 MPa). 6. For plants grown in full sun under water stress, NS exhibited 23% mortality, FS 60% and OS 35% mortality, while irrigated controls had greatly reduced mortality across all life histories. Among shade grown plants under water stress, NS exhibited 30% mortality, FS 20% and OS 1% mortality. This pattern of differential mortality was the same for irrigated plants indicating that water stress was not the cause of mortality in the shade. 7. Greater stem and root resistance to water stress induced cavitation were strongly correlated with lower percent mortality during the summer dry season suggesting a link between these traits and fitness. 8. Synthesis . This study finds a link between life history type and water stress tolerance. Consistent with open canopy specialization, NS survived best in full sun. The FS and OS life history type had better survival in the shade. The OS was unexpectedly versatile, surviving well in the sun and shade. The evolutionary history of the life history types is discussed as an important factor in linking water stress tolerance and life history.

Reproductive allocation of Carex flava reacts differently to competition and resources in a designed plant mixture of five species

In natural plant communities, reproductive allocation can be affected by complex interactions among abiotic resources, species competition and plant size. This topic was addressed using a variety of designed mixed stands of five species (Carex elata, Carex flava, Lycopus europaeus, Lysimachia vulgaris and Mentha aquatica) under four abiotic conditions to investigate how competition and abiotic resources influence the reproductive allocation of one of the five species, C. flava. The plant mixtures varied systematically in both the relative abundance of the five species and the absolute density, and were each established with two levels of water and nutrients. In total, 176 mixtures were maintained for two growing seasons in large pots in an experimental garden. Reproductive allocation of C. flava increased from 6.8% to 9.7% under high nutrient application; however, for both nutrient levels, reproductive allocation was independent of shoot mass (size-independent allocation). Under low competition, reproductive allocation of C. flava decreased as its shoot mass increased, indicating a relatively high investment in vegetative structures under higher light availability. However, under strong competition, the allocation pattern changed and a constant reproductive allocation for different plant sizes was observed. Different water levels did not influence the shoot mass, seed mass or reproductive allocation of C. flava, indicating that the species was not stressed under dryer conditions. When under competitive pressure, however, the species responded with reduced shoot and seed production under more favourable water conditions. This behaviour indicates a trade-off between the ability to tolerate stress and the competitive and reproductive response of C. flava. In conclusion, C. flava was adversely affected by competition with some of the species, and competition, mediated by plant size, indirectly affected reproductive allocation. C. flava was able to modify its allocation pattern depending on the available resources and retained its reproductive allocation even under unfavourable conditions for varying plant sizes, which is interpreted as an advantageous reaction to greater competition pressure.

Root plasticity of native and invasive Great Basin species in response to soil nitrogen heterogeneity

Soil nutrients are heterogeneously distributed in natural systems. While many species respond to this heterogeneity through root system plasticity, little is known about how the magnitude of these responses may vary between native and invasive species. We quantified root morphological and physiological plasticity of co-occurring native and invasive Great Basin species in response to soil nitrogen heterogeneity and determined if trade-offs exist between these foraging responses and species relative growth rate or root system biomass. The nine study species included three perennial bunchgrasses, three perennial forbs, and three invasive perennial forbs. The plants were grown in large pots outdoors. Once a week for 4 weeks equal amounts of 15NH4 15NO3 were distributed in the soil either evenly through the soil profile, in four patches, or in two patches. All species acquired more N in patches compared to when N was applied evenly through the soil profile. None of the species increased root length density in enriched patches compared to control patches but all species increased root N uptake rate in enriched patches. There was a positive relationship between N uptake rate, relative growth rate, and root system biomass. Path analysis indicated that these positive interrelationships among traits could provide one explanation of how invasive forbs were able to capture 2 and 15-fold more N from enriched patches compared to the native grasses and forbs, respectively. Results from this pot study suggest that plant traits related to nutrient capture in heterogeneous soil environments may be positively correlated which could potentially promote size-asymmetric competition belowground and facilitate the spread of invasive species. However, field experiments with plants in different neighbor environments ultimately are needed to determine if these positive relationships among traits influence competitive ability and invader success.

Where Johannes Brahms Was Born

Where Johannes Brahms Was Born Eric Gabriel Lehman Joel pauses on the little terrace before Hanne's front door. She'll certainly shoot him a look with those large eyes of hers when he waltzes in at 11 in the morning, even if it is Pascal, her wild 14-year-old, who needs the talking-to. But Hanne has been around the block. She understands what it means to search for love. The courtyard is strewn with bottles and plastic cups from last night's Bastille Day celebrations. Buildings on either side of the courtyard are laced together by strings of colored bulbs, their light feeble in the sun. Once a third building enclosed the courtyard but it didn't survive the war and now the yard opens to the street like a window. Hanne claimed to have rented the house because of the yellow plum tree that arches over it and bears translucent, golden fruit. "Morgen." Pascal sits naked, framed by his window, writing in a notebook, song lyrics for his band perhaps. The sill is where he used to chat with Sybille, his girlfriend from across the courtyard until she dumped him the week before. One leg shields from view what is not meant to be seen, but only just, an arrangement of discretion and tease executed by someone who knows people look at him. A shell hangs from a leather thong around his neck and a sliver of earring shines through thickets of hair. He is tall for his age, lithe, and dark-eyed. His position has him lit to the best advantage; sunlight burnishes his calf and dabs a shoulder. Joel imagines standing close enough to breathe in the naked Pascal as he might a handsome stranger waking beside him. Pascal's knowing smile reads Joel's mind. "Congratulations. You're the first schwul American I've met," he had said after Joel moved in. He let Joel know that he'd had erotic encounters [End Page 205] with male friends, even if he is drawn to women "at the moment." It is hard imagining a kid his age in Dubuque speaking with such poise, and Pascal clearly enjoys playing the enlightened northern European. He returns to his writing, allowing Joel—and Sybille—to observe him so engaged. He'll be the first thing she sees when she looks out of her window, part of Pascal's plan to get her back, Joel supposes. Joel feels like a native with a paper bag of Brötchen from the local bakery, ordered in German, more or less. He has been in Hamburg for a little over a year and sleeps on Hanne's couch in return for hauling cases of mineral water down to her basement cabaret, working the espresso maker and sweeping up, and he fills in if a singer needs a pianist, too. Hanne's cabaret is stuck in an anarchist/hippie-flavored time warp of the sort Joel associates with college coffeehouses. Last night Beate Schumacher sang blues with a distinctly Prussian lilt: Sommertihme, when ze living ist eassy... Hanne has asked her back in a couple of weeks. Germans love die Blues. Beate Schumacher told Joel that when she goes to New York in the fall she will head straight to Harlem and not waste time in museums. "Blacks, zey are ze real Americans," she says. "Zey have soul." The large front room is clear of last night's debris left over from post-show carousing; so Hanne must have gotten up especially early that morning, a bad sign, because it also means that Todd hadn't stayed over. Pascal's artwork fills the living room walls and an entire corner is taken up by his drum set. A radio crackles in the kitchen. "Bonjour, mon petit." Hanne's French is left over from her time in Lyon when she still lived with Pascal's father. Her cigarette is gummed between her lips as she heaves a large cooking pot into the dish drainer. "You look half asleep, Liebling. There's coffee." Her henna-red hair is the color of the velvet used to line jewelry boxes and is pulled back, shiny as...

Growing sunflower plants from seed to seed in small pots in greenhouse

This paper reports the results of two experiments in which sunflower plants were grown from seed to seed in small pots to utilize greenhouse space efficiently. We used small plastic pots (9.0 × 8.6 × 9.0 cm) filled with approximately half a liter of potting soil in a temperature-controlled greenhouse with a light : dark cycle of 14 : 10 h. In the first experiment, 100 F2:5 plants were grown on a two-square-meter bench in the greenhouse during the winter of 2007. Ninety-eight of the 100 plants survived to maturity and produced an average of 62 viable seeds with a range of 36 to 102 seeds per plant. In comparison to the plants grown in six-liter pots, we observed that all the plants grown in the small pots had a significant decrease in plant size such as height, head diameter, and number of seeds per plant. The plants grown in the small pots flowered on average 9 days later than those in the large pots. No significant difference was observed for germination rate between the seeds harvested from small and large pots. In the second experiment, two oilseed and two confectionery sunflower inbred lines were grown during the summer of 2007 to confirm the observations from the first experiment. The results were essentially the same as those observed in the first experiment. For number of seed produced per plant, an average of 13.0 to 42.2 seeds were obtained per head for each of the four lines grown in small pots, with no significant difference observed between oil and confectionery sunflower. Thus, our results suggest that it is possible to produce viable seeds from plants grown in small pots. This method should be useful for efficient line advancement in the greenhouse for breeding and genetic studies.

First Report of Anthracnose of Salal Caused by Colletotrichum acutatum in British Columbia

Gaultheria shallon Pursh (salal) is a native, Pacific Northwest forest understory plant produced by numerous commercial nurseries as a garden and landscape ground cover. Seed is sown in soilless media in greenhouse plug flats, and seedlings are transplanted into larger pots at 24 to 36 weeks. In October 2005, approximately 30% of 16-week-old G. shallon Pursh (salal) seedlings in a commercial greenhouse in coastal British Columbia, Canada were observed to be dying back. Black, water-soaked, cankers girdled the stems and petioles resulting in seedling necrosis. Cankers extended into the base of affected leaves, and irregular, black leaf spots with concentric rings were observed. A Colletotrichum sp. was isolated on potato dextrose agar (PDA) + 0.005% streptomycin. In May 2006, 160 20-week-old salal seedlings (two- to five-leaf stage) in four plug cell flats of 40 seedlings each were inoculated with a hand atomizer with a mycelial and spore suspension of approximately 1 × 108 CFU/ml (dilution plating) in 100 mL sterile dH2O; 120 seedlings (four flats of 30 seedlings each) were sprayed with water alone. Flats were covered with black plastic for 48 h and then placed randomly in a shaded greenhouse at 14 to 22°C with overhead watering. The percentage of necrotic seedlings with black, water-soaked cankers and leaf spots in the inoculated flats at 1 to 8 weeks was 3.8, 7.6, 8.2, 16.4, 44.9, 62.0, 79.7, and 81.6, consecutively; versus 2.5% at 8 weeks in the noninoculated flats. Infection of the noninoculated seedlings was presumably due to spore splash from irrigation. Both the original isolate used as inoculum and colonies reisolated on PDA from inoculated, surface-sterilized, symptomatic tissues were identified as Colletotrichum acutatum J.H. Simmonds based on morphology (2) and PCR using a species-specific primer (1). Hyaline, aseptate, fusiform conidia, measuring 8 to 16 × 2.5 to 4 μm, were produced in acervuli without setae on plants and in culture. The teleomorph (Glomerella) stage was not observed. To our knowledge, this is the first report of an anthracnose disease of salal.

'UF Multi-flora Peach' and 'UF Multi-flora Pink Frost' Gerberas - University of Florida Cultivars for Landscapes and Large Pots

ENH-1043, a 5-page illustrated fact sheet by Zhanao Deng and Brent K. Harbaugh, describes two gerbera cultivars developed at UF specifically for landscape use, their origin, container and garden performance, and availability. Includes references. Published by the UF Department of Environmental Horticulture.

The plasticity of organ size and anatomy

Leaf size of many, if not most, annuals is correlated with the rate of development, or vigor, of individual plants and even of individual branches. Two related questions were considered: whether there are vigor-dependent anatomical differences between leaves of different sizes, and whether organ size could be a neglected plasticity, a response to the overall state of the plant rather than to specific environmental cues. Senecio vernalis plants were grown outdoors in pots of three sizes. When the first capitula appeared, groups of plants were transferred from small and medium pots to large pots. There were 7-fold surface area differences between comparable leaves of plants in small and in large pots. Leaves that had been fully formed when plants were transferred to large pots caught up;, reaching the leaf sizes characteristic of their new conditions. Stomata densities, vein length per unit area, and cross sections of palisade cells were measured. These parameters differed in large and small leaves, and t...

Impact of chipping residues and its leachate on the initiation and growth of aspen root suckers

Field chipping operations often disperse chipping residues of bark and branches in layers or piles in cut-overs. We tested the effects of these residues on the root sucker regeneration of aspen (Populus tremuloides Michx.), using root systems established in large pots. After decapitation of the stems, the root systems were covered with a 4 cm thick layer of chipping residues. Other root systems were treated with an extract of the water-soluble compounds leached from a similar amount of residues while others were left untreated as controls; all three treatments were left to sucker for 7 wk. There were no differences in the number of root suckers that were initiated on the aspen root system among the three treatments. There were, however, significantly lower numbers of suckers that emerged through the chipping residue and their emergence was delayed relative to the other treatments. The delay in emergence and the reduction in sucker numbers were likely a result of the residues acting as a physical barrier. After 7 wk, concentrations of water-soluble phenolic compounds, sugars, and carbon from the chipping residues were elevated in the soil; however, they appeared to be below a level that affects sucker emergence and development. Key words: Allelochemistry, leachate, physical barrier, Populus tremuloides, regeneration

Domestication and Crop Physiology: Roots of Green-Revolution Wheat

Background and AimsMost plant scientists, in contrast to animal scientists, study only half the organism, namely above-ground stems, leaves, flowers and fruits, and neglect below-ground roots. Yet all acknowledge roots are important for anchorage, water and nutrient uptake, and presumably components of yield. This paper investigates the relationship between domestication, and the root systems of landraces, and the parents of early, mid- and late green-revolution bread wheat cultivars. It compares the root system of bread wheat and ‘Veery’-type wheat containing the 1RS translocation from rye.MethodsWheat germplasm was grown in large pots in sand culture in replicated experiments. This allowed roots to be washed free to study root characters.Key ResultsThe three bread wheat parents of early green-revolution wheats have root biomass less than two-thirds the mean of some landrace wheats. Crossing early green-revolution wheat to an F2 of ‘Norin 10’ and ‘Brevor’, further reduced root biomass in mid-generation semi-dwarf and dwarf wheats. Later-generation semi-dwarf wheats show genetic variation for root biomass, but some exhibit further reduction in root size. This is so for some California and UK wheats. The wheat–rye translocation in ‘Kavkaz’ for the short arm of chromosome 1 (1RS) increased root biomass and branching in cultivars that contained it.ConclusionsRoot size of modern cultivars is small compared with that of landraces. Their root system may be too small for optimum uptake of water and nutrients and maximum grain yield. Optimum root size for grain yield has not been investigated in wheat or most crop plants. Use of 1RS and similar alien translocations may increase root biomass and grain yield significantly in irrigated and rain-fed conditions. Root characters may be integrated into components of yield analysis in wheat. Plant breeders may need to select directly for root characters.