FI Plants Research Articles

Thermal imaging to phenotype traditional maize landraces for drought tolerance

Searching and identification of new crops or varieties with higher adaptation or resistance to water stress is one of the strategies to make agriculture profitable and more sustainable. Especially en arid and semi areas with limiting water resources. This study establishes a practical, fast and replicable protocol to select maize genotypes for its capability to respond to water stress. Eight Portuguese maize landraces (LD), traditionally grown in areas with different altitude and subjected to potentially different degrees of water stress (low altitude = potentially lower stress; high altitude = potentially higher stress) was used. Seedlings were subjected to continuous watering (FI) or forced to water withholding (non-irrigated) for a period of 7-8 days followed by re-watering (NI). Leaf temperature was determined every 48 h by thermal imaging and the temperature difference between NI and FI plants (ΔTNI-FI) was calculated. We found that those genotypes that traditionally had been grown at higher altitudes kept more stable leaf temperature values under dry or wet conditions (small ΔTNI-FI) even under severe water stress. These results will help to optimize a screening protocol for maize seedlings and select novel genotypes or LDs better adapted to water stress, especially in regions where irrigation water is scarce.

The Effect of Partial Root-zone Drying on Tomato Fruit Growth

Tomato fruit growth and productivity are complex processes depending on the interaction between physiological, genetic and environmental factors. Under current climate conditions of drought and scarce water supply, the challenge is to increase water use efficiency and to sustain tomato yield. Partial root-zone drying technique (PRD) is one of the irrigation methods with the potential to increase the water use efficiency and sustain the yield of many crops including tomato. The aim of presented results was to investigate the effects of PRD on tomato fruit growth, the activity of cell wall-associated peroxidase and ABA content in pericarp of tomato cultivar Ailsa Craig.The experiment was done in controlled conditions and plants under PRD received 70% of water given to full irrigated plants (FI) plants. In PRD irrigation is applied to one half of the root system while the other half dried down and then the treatment was reversed. ABA content in fruit pericarp was measured by ELISA test and cell wall-associated peroxidase activity by a guaiacol test.Fruit growth parameters showed that the maximal growth rate was significantly higher in FI plants than PRD but because the longer period of cell expansion the final diameter of PRD tomato fruits was slightly higher in PRD than in FI fruits. ABA content in tomato pericarp declined during the tomato development until the end of cell growth phase without significant differences between PRD and FI treated plants. The activity of peroxidase was significantly higher in PRD compared to FI. The significantly increase in the activity of enzyme cell wall-associated peroxidase in tomato fruit pericarp under PRD conditions coincided with the end of cell growth and the beginning of the ripening process. These results pointed out that this enzyme may control tomato fruit maturation.

Plasticity in stomatal size and density of potato leaves under different irrigation and phosphorus regimes

The morphological features of stomata including their size and density could be modulated by environmental cues; however, the underlying mechanisms remain largely elusive. Here, the effect of different irrigation and phosphorus (P) regimes on stomatal size (SS) and stomatal density (SD) of potato leaves was investigated. The plants were grown in split-root pots under two P fertilization rates (viz., 0 and 100mgkg−1 soil, denoted as P0 and P1, respectively) and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation regimes. Results showed that SS and SD were unresponsive to P but significantly affected by the irrigation treatment. FI plants had the largest SS, followed by DI, and PRD the smallest; and the reverse was the case for SD. Compared to FI and DI, PRD plants had significantly lower values of specific leaf area (SLA) and leaf carbon isotope discrimination (Δ13C) under P0. Midday leaf water potential (Ψleaf) and stomatal conductance (gs) was similar for DI and PRD, which was significantly lower than that of FI. Leaf contents of C, N, K, Ca and Mg were higher in PRD than in DI plants, particularly under P0. When analyzed across the three irrigation regimes, it was found that the P1 plants had significantly higher leaf contents of P and Mg, but significantly lower leaf K content compared to the P0 plants. Linear correlation analyses revealed that SS was positively correlated with Ψleaf and Δ13C; whereas SD was negatively correlated with Ψleaf, Δ13C and SLA, and positively correlated with leaf C, N and Ca contents. And gs was positively correlated with SS but negatively correlated with SD. Collectively, under low P level, the smaller and denser stomata in PRD plants may bring about a more efficient stomatal control over gas exchange, hereby potentially enhance water-use efficiency as exemplified by the lowered leaf Δ13C under fluctuating soil moisture conditions.

TEHNIKA REDUKOVANOG NAVODNJAVANJA ZA SMANJENO KORIŠĆENJE VODE KOD PARADAJZA U USLOVIMA PLASTENIKA

The aim of paper was to asses the use of regulated deficit irrigation (RDI) for production of two tomato cultivars (Cedrico and Abellus) in polytunnels in Serbia. RDI plants received 60% of the water that was applied to FI plants and significant saving of water for irrigation and increased in irrigation water use efficiency (IWUE) were achieved. Yield data for Cedrico cultivar showed no differences between RDI and FI, while due to the bigger sensitivity to drought, yield of Abellus was reduced under RDI. In general, fruit quality (soluble solids, titrable acidity) was sustained or improved in both cultivars under RDI. Economic analyses showed that due to the current low prices of water and electricity in Serbia, the profit increase of Cedrico, similarly to the previously trialed cultivar Amati, was not high under RDI comparing to FI. Reduction of yield and consequent profit for Abellus, indicated that for future commercial growing of tomato under RDI should be used drought resistant cultivars.

Leaf anatomy and photosynthetic acclimation in Valeriana jatamansi L. grown under high and low irradiance

Relationship of leaf anatomy with photosynthetic acclimation of Valeriana jatamansi was studied under full irradiance [FI, 1 600 μmol(PPFD) m-2 s-1] and net-shade [NS, 650 μmol(PPFD) m-2 s-1]. FI plants had thicker leaves with higher respiration rate (RD), nitrogen content per unit leaf area, chlorophyll a/b ratio, high leaf mass per leaf area unit (LMA), and surface area of mesophyll cell (Smes) and chloroplasts (Sc) facing intercellular space than NS plants. The difference between leaf thickness of FI and NS leaves was about 28 % but difference in photon-saturated rate of photosynthesis per unit leaf area (PNmax) was 50 %. This indicates that PNmax can increase to a larger extent than the leaf thickness with increasing irradiance in V. jatamansi. Anatomical studies showed that the mesophyll cells of FI plants had no open spaces along the mesophyll cell walls (higher Sc), but in NS plants wide open spaces along the mesophyll cell wall (lower Sc) were found. Positive correlation between Sc and PNmax explained the higher PNmax in FI plants. Increase in mesophyll thickness increased the availability of space along the mesophyll cell wall for chloroplasts (increased Sc) and hence PNmax was higher in FI plants. Thus this Himalayan species can acclimate to full sunlight by altering leaf anatomy and therefore may be cultivated in open fields.

Partial rootzone drying: effects on growth and fruit quality of field-grown grapevines (Vitis vinifera).

A study to assess the effects of the Partial Rootzone Drying (PRD) irrigation strategy in comparison to other irrigation systems was carried out in southern Portugal in two field-grown grapevines varieties, Moscatel and Castelão. We addressed the question of whether by regulating growth and plant water use, the PRD system would enable an equilibrated vegetative development, leading to a favourable capture of solar radiation for photoassimilate production and, at the same time to provide an optimum environment for fruit maturation. Three irrigation schemes were applied in addition to the non-irrigated (NI) vines: partial root drying (PRD), 50% of crop evapotranspiration (ETc), supplied to only one side of the root system while the other one was allowed to dry, alternating sides every 15 days; deficit irrigated (DI), 50% ETc supplied, half to each side of the root system and full irrigated (FI, 100% ETc). During the whole season FI plants of both varieties exhibited a high leaf predawn water potential (ψpd , ca-0.2MPa) while a progressive decline was observed in NI plants, reaching ψpd values near -0.7 MPa at the end of August. PRD and DI presented intermediate values. PRD vines exhibited a stronger control over vegetative growth as compared with DI and FI plants. This was expressed by lower values of total leaf area at harvest, leaf layer number, canopy wideness and water shoots number, allowing a higher light interception at the cluster zone that induced an improvement in some berry quality characteristics. Watering had no significant effects on sugar accumulation in the berries but led to a favourable increase in the must titratable acidity, mainly in Castelão. Whereas in DI and FI treatments berry skin anthocyanins and phenols content were always lower than in NI, in PRD there was either no reduction or the reduction was much lower than in the other irrigation treatments. Water use efficiency (WUE) was increased by about 80% in PRD and DI when compared with FI, as a result of almost similar yields in the three treatments. Yield gains of irrigated plants in relation to NI were modest, explained by the rainy spring in both years.

Perbanyakan Padi Fl Interspesifik untuk Bahan Silang Balik (Back Cross)

A lot of plant materials are needed for successful back cross program of interspecific FI rice to their recurrent parents. Multiplication of the steril FI plants through tiller propagation is not adequate. The research aims to develop technique of vegetatif multiplication of interspesific hybrid rice utilizing nodal segments. In the vegetatif multiplication experiment, several factors were examined as treatments: nutrition culture (MS, Yoshida, and water), stum position (first, second and third) and growth media (vermiculite, husk charcoal, and sand). The plant materials are interspecific FI rice i.e. Ranah Sanra (genom AA) x O. officinalis 100870 (genom CC), Hawara Bunar (genom AA) x O. Punctata 9101411 (genom BB), Grogol (genom AA) x O. punctata 9101411 (genom BB), CT 6510-24-1-3 (genom AA) x O. malamphuzaensis 100957 (genom BBCC). Results of the study indicated that MS and Yoshida nutrition, stum without sheath, base of stum and sand media gave better growth more than other treatments. Key words: Vegetatif multiplication, FI interspecific

Production of Double Haploids via Maize Pollination in Wheat

SUMMARY Seven good agronomic wheat varieties lacking Karnal bunt tolerance were crossed with two Karnal bunt tolerant varieties. The Fi plants from these crosses were crossed with diverse maize lines. Immediately after pollination solution containing 2,4-D (50mg/l) + GA3 (100mg/l) was injected into upper most node. After 24 hours florets of the pollinated spikes were flooded with same solution. The pollinated spikes were harvested 13 to 16 days post pollination and were taken for rescuing embryos. Rescued embryos were used to obtain callus as well as direct plant embryogenesis. The haploid plantlets and the embryoids of haploid calli were converted to double haploids (DH) using colchicine. For DH production the direct germination of rescued embryos followed by colchicine treatment of haploid plantlets figured to be more efficient method than obtaining plant via haploid callus

Responses involved in increased dry matter production with supplementary incandescent radiation in growth chambers

Glycine max was grown in controlled environment chambers under fluorescent lamps supplemented with incandescent lamps (FI) or under fluorescent lamps alone (F). Dry matter production was greater for FI plants than for F plants between 7 and 28 days after emergence. Leaf temperature was also greater for FI plants, but the CO 2 exchange rates of the third trifoliolate leaf and the rates of vegetative development were not different between FI and F plants. Relative growth rates were not different between FI and F plants from 7 to 28 days after emergence.

Inheritance of Flowering Date in Cicer Milkvetch1

Flowering date is an important characteristic of cicer milkvetch (Astragalus cicer L.) because of its potential relationship to forage yield. Therefore, cicer milkvetch was evaluated in a 10‐parent diallel cross for flowering score (profuseness of flowering) in the seedling year and for flowering date in the seedling year and in two growth periods of the 2nd year. The F1 progenies and their reciprocals were grown under irrigation. Significant differences occurred among crosses for all traits. The variance for these traits was partitioned into general combining ability, specific combining ability, and reciprocal effects. Each of these components was significant for all traits. When plants from late ✕ early flowering crosses were classified as either flowering or nonflowering in the seedling year, flowering (vernalization not required) was partially dominant to nonflowering (vernalization required). In the seedling year, 73% of all FI plants flowered while 98% flowered in each of the two growth periods of the 2nd year. In general, plant vigor over all growth periods was poorly correlated with flowering date. It will be possible, however, to select vigorous plants which flower early in all three growth periods.

RECENT BARLEY MUTANTS AND THEIR LINKAGES II. GENETIC DATA FOR FURTHER MUTANTS

Introduction In this report data are presented from linltage studies of a group of mutants and genetic stoclts assembled at the University of Alberta. Some of the results have been described briefly in prelinlinary reports (Wallter, Kasha and Miller, 1958; Wallter and i\/liller, 1958). Others are from a continuation of the study of eight mutants reported in the first article of this series (Kasha and Wallter, 1960). T h e remainder are from studies to attempt a further delineation of the l inl ta~e ~ r o u p on chromosome 6. a. S ~nce these studies are part of a larger project \vl~ose prin~ary objective is the production of ~nultiple recombinants, it has not usually been possible to carry out the additional studies that would be necessary to establish the location of the mutant genes on the linltage maps. This information will be sought during the course of further recombination of the mutant and recessive rnarlter alleles within each of the linltage groups. The characters described are those for which indications of linltage were e~lcountered in these studies. T h e descriptions and independence data for a further group that has not yet sh0u.n linltage have been reserved for future reports. Methods Crosses were verforined after hand-emasculation and. to eliminate the DOSsibilitv of accidenial selfinp. F , ~ l a n t s were checlted for tl;e presence of d o k n U' 1 ant genes received from the pollen parents. Variegated ndtants were used as pollen parents of crosses, to avoid the possibility of cytoplasn~ic transmission of variegation through the egg. The progenies of individual FI plants f rom crosses involving mutants maintainable only through heterozygotes (malesterile-10) were grown in separate plots, and only those segregating for the mutant character xvere classified for linltage analysis. T h e F,'s were field-planted with a modified V-belt seeder, designed by J. Fitzsin~mons, Parkland Farm, University of Alberta, that gave a regular spacing of sinple lternels but did not ~ e r m i t ' t h e detection of permination failures. u. U Progenies segregating for c111ord~l1~11 mutants were classified at both the seedling and the heading stage and the mutant plants were marked with colored tags for identification at harvest. Those progenies segregating for n~orphological foliaee characters and for s ~ i l t e characters not ex~ressed in all tillers were also U 1 I classified in the field. durinp harvest. For the analvsis of other svilte characters. u i I a single spilte was removed from each F2 plant. These spiltes were stored in inanilla bags, a separate bag for each field-classified phenotype, and were later classified for the spilte characters in the laboratory. Both F,'s and F,'s were checlted carefullv for ovule sterilitv and those F2 vrbpenies in which it occurred i J 1 U were field-classified for sterility after examining several spiltes per plant. T h e partition of i' described by Mather (1951) for obtaining the x2 value for linltage (x,,'), and the product-moment method of determining the percent-