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A number of morphological, physiological and phenological traits are known to improve the performance of rice challenged by drought. Root morphological traits and stress-induced response form important components of drought tolerance. Enhancing grain yield remains the principal objective of most breeding programs. Interaction between primary traits poses a formidable challenge while dealing with grain yield under stress. The evaluation of root morphology at three different growth stages and grain yield along with related characteristics under contrasting moisture regimes was made using nine backcrosses along with their parent and standard checks. The backcrosses invoved transgressant double haploid lines derived from IR64 and Azucena with IR64. Marked genotypic differences were observed for all root morphology as well as grain yield related characteristics across the sampling dates as revealed by individual and combined ANOVA. Among the nine backcrosses studied in this experiment, the BC1F2 population of P124 x IR64 were evaluated for forwarding based on their performance with respect to maximum root length and grain yield under both well-watered and low-moisture stress conditions. Sixtynine plants - ten percent of the backcross population - were selectively genotyped using RAPD primers. Under well-watered conditions two RAPD markers showed strong linkage to QTLs for maximum root length evaluated under ww conditions. Two other markers could explain the considerable amount of variation in MRL under LMS. One of the markers identified under low-moisture stress conditions was also able to explain variability in maximum root length in the mean environment.
Broad bean (Vicia faba L. “Inovec”) seeds were artificially aged by means of storage at 30 %, resp. 25 % water content at 25 °C for 7-days to study the consequences on germination, root length and frequency of chromosomal aberrations. Under these conditions, significant changes in all parameters were observed. An increase of frequency of chromosomal aberrations in ana-telophase cells was confirmed by evaluation of c-metaphase cells. Synergic effect of artificial seed ageing was studied on different harvests of old seeds. Possible principles of this effect on cell level are discussed.
The present study was conducted in order to determine the effect of gamma rays and EMS on seed germination, Seedling height and root length in chick pea to identify the lethal dose (LD50). In this regard, the healthy seeds of chick pea was subjected to different doses/concentrations of gamma rays (20, 30, 40, 50 and 60kR) and EMS (10, 20, 30, 40 and 50mM) for inducing mutation. The effect of gamma rays and EMS was determined by measuring the seed germination, seedling height and root length under the conditions of the M1 generation. The results shows that, the seed germination, seedling height and root length were significantly decreased with increasing doses/concentrations. The LD50 values were observed based on the growth reduction of seedlings after treatments with mutagen. The effective doses/concentrations which caused 50% growth reduction were observed in 40kR in gamma rays and 30mM in EMS.
Effect of plant growth regulators on seed germination and seedling characters in terms of root length and shoot length. The seeds of sesame variety TVM – 1 were treated with different concentration of gibberlic acid (1.0, 2.0, 3.0 and 4.0 mg/l) and indole acetic acid (1.0, 2.0, 3.0 and 4.0 mg/l). From the results, it was observed that the GA3 and IAA at 2.0mg/l had regulatory effect on seed germination and seedling characters. Maximum germination, root length and shoot length was observed at 2.0mg/l in GA3 and 2.0mg/l in IAA than control. And GA3 at 2.0gm/l was found to be more efficient to modify seed germination and seedling characters when compared to IAA and control.
Cyclic pedigree selection for longer seminal roots was performed in the F₂, F₃ and F₄ generations of hybrid population of spring barley. The total length of roots was measured in seedlings grown in filter-paper rollers. The intensity of selection was 20% (C₁, C₂ cycles) and 26% (C₃). Selection was effective. On an average, the finally selected F₅-pedigrees formed 6% longer seminal root system than the initial F₂'s and much of them exhibited 7-16% improved rooting when compared with the best parent in a sand-vermiculite pot culture. Realized heritabilitiy coefficient of the root length ranged from 0.21 to 0.37 when assessed by the ratio of selection response to selection differential, while those estimated by the parent- offspring regressions attained 0.40-0.53. The obtained results suggest that progeny evaluation and/or selection delayed for later generations should be essential for more effective root selection in barley.
Plants, as well as their residues (mulches), release physiologically active substances (allelochemicals), which may affect plant germination, development, and productivity. In this study we investigated the allelopathic effects of aqueous extracts of organic mulches (winter wheat straw, peat, sawdust, and gramineous grass) at different concentrations on germination and early growth of radish (Raphanus sativus L.), carrot (Daucus sativus Röhl.), and lettuce (Lactuca sativa L.). It was found, that the strongest negative effect on the germination and shoot and root development of investigated vegetables was with the highest concentration (1 : 10) of the grass aqueous extract. Peat mulch aqueous extracts had the least negative impact on all vegetable seed germination. Straw and peat mulches stimulated the early growth of R. sativus shoots, but there was a negative affect on D. sativus shoot development. The aqueous extracts of various organic mulches had negative effects on R. sativus, while mostly positive effects found on L. sativa root development.
W pracy przedstawiono wyniki trzyletniego doświadczenia polowego przeprowadzonego w Ogrodzie Botanicznym IHAR w Bydgoszczy. Ocenie poddano trzy mieszanki kępowych traw gazonowych. Komponentami mieszanki pierwszej (M I) były Festuca rubra (75%) i Lolium perenne (25%), W skład mieszanki drugiej (M II) wchodziły Festuca arundinacea (30%), Festuca ovina (50%) Lolium perenne (20%), Mieszankę trzecią (M III) tworzyły Festuca ovina (30%), Festuca rubra (35%) oraz Festuca heterophylla (35%). Ocenę systemów korzeniowych traw i innych cech trawników dokonywano w trzech terminach: wiosną (maj), latem (lipiec) i jesienią (październik). W wyniku przeprowadzonych badań stwierdzono, że zagęszczanie gleby wpłynęło istotnie na zmniejszenie masy korzeni w porównaniu do powierzchni kontrolnych. Wyższe plony masy nadziemnej zarówno w formie ścierni, jak i zielonej masy koszonej, z wyjątkiem mieszanki MII, uzyskano na powierzchniach kontrolnych, z czego największe dla mieszanki M I a najsłabsze dla mieszanki M III. Zmniejszenie długości korzeni było bardziej zróżnicowane, z czego pozytywnie na wzrost długości korzeni traw w warunkach większego zagęszczenie gleby reagowała M II. Zagęszczanie gleby wpłynęło negatywnie na ogólną ocenę trawnikową i stopień zadarnienia ocenianych powierzchni trawnikowych.
Maize (Zea mays L.) occupies one of the important cereal crops all over the world. It serves as food and oil for human, feed for livestock and as raw material for industry [1], [2]. It is widely grown in various soil and climatic conditions due to its contribution among cereals in the world. It can play a glorious role in economy of the country by feeding malnourished people as well as solving food problems. Therefore, maize should get priority considering the protein malnourishment of the people, because it encompasses more digestible protein than the other cereals [3]. Furthermore, due to the rising poultry industry in Bangladesh, the need for maize is increasing very sharply as maize is an important component of poultry feed. In Bangladesh, total land area and production of maize are 395500 ha and 279500 m tons respectively [4]. The world agriculture faced lots of problems due to soil salinity as its damage the various cellular function of plant. The land is becoming non-productive due to accumulation of salt in fresh soil through tidal flow close proximity to sea level in each year. About 300 million ha of irrigated farmland is estimated to be affected by salinity. Four countries viz. China, India, Pakistan and United States provided more than half of all salt-affected irrigated farmlands in the world [5]. The most severe difficulties for crop production in the dry regions are high concentration of toxic ions especially NaCl either in soil or in irrigation water [6]. Plant growth and productivity drastically restricted by salinity that is of the major environmental factors [7]. The salt stress could be lead to a decrease in the growth and productivity of various crops in the world [8-16]. The disruption of intracellular ionic concentration and osmotic gradients inhibiting a number of vital physiological functions reduced by salinity resulting malfunctioning of plant morpho-physiological characters i.e photosynthesis [17], reduction of protein synthesis and activities of enzyme [18], poor nutritional balance (lowering N, P, K⁺, Ca²⁺ unbalanced carbon metabolism) [19], and stunted stem length, stem width, stempith diameter, leaf blade thickness, leaf vascular bundle length and leaf xylem vessels [20], [21]. Reduction of nutrient uptake capacity often accompanied by mineral toxicity leading to nutritional imbalance [22]. Soil reclamation and/or improved irrigation techniques (generally expensive) could be a systematic tactics for the management of problematic soils/salt affected soil in the arid and semi-arid tropics of this universe. The most inexpensive and more sustainable solution for using these problematic soils is the crop improvement through genetically or agronomical management. So, improvement of new methods to introduce salt stress resistance and tolerance varieties is so important. By cultivating the tolerant genotype that may sustain a reasonable yield on salt affected soil [23]. The germination and tolerance mechanism greatly varied in crop to crop at growth and seedling stage [24]. The selection criterion for screening salt tolerant individual and increasing salt tolerance in many species is the vigorous growth at the seedling stage [25]. Among all of the life cycle of plant, the germination and seedling stage is the sensitive to salinity than the adult stage [26]. The greater reduction of early seedling and growth stage was observed in wheat and sorghum with increasing salinity [27]. Therefore, the present experiment was carried to evaluate salt tolerance of four maize varieties at germination and seedling growth under saline stress environment.
The effects of different concentrations (10,20,30,40 and 50 ppm) of cadmium chloride on seed germination, root length, shoot length, fresh weight, photosynthetic pigments, protein content and peroxidase activity in tomato (Lycopersicon esculentum L.). Higher concentration of Cadmium were reported specially at 40 and 50 μm reduced germination significantly. Leaf chlorosis, wilting and leaf abscission were observed in plants with cadmium. Protein content and sugar content were reduced in higher concentrations of cadmium. However, lower concentrations of CdCl2 resulted in higher peroxidase activity in roots and shoots of tomato.
Aqucous leaf extract of common lambsquarters (Chenopodium album L.) was evaluated alone or in combination with NaCl for its effect on germination and rice seedling growth. The treatments have no effect on germination. However, growth of both shoot and root significantly decreased under NaCl alone and in combination with leaf extract. Root growth was affected more than the shoot and the effect of NaCl was accentuated in the presence of leaf extract.
Dziedziczenie szeregu morfologicznych cech systemu korzeniowego analizowano w diallelicznym układzie krzyżowań (Ps + F₂s) pszenicy ozimej. W czynnikowym doświadczeniu wazonowym, przeprowadzonym w fitotronowej komorze wzrostowej, rośliny rosły w specjalnych wazonach (tzw. 'root box’) w warunkach kontrolnych (K), suszy (D) i obniżonego zaopatrzenia w azot (N). W stadium krzewienia (stadium 21/22 Zadoksa) korzenie oddzielono od podłoża przez delikatne wymywanie, a ich cechy zmierzono przy pomocy specjalnego systemu pomiarowego. Efekty GCA okazały się najistotniejsze dla wariancji większości cech, z wyjątkiem całkowitej długości korzeni (TLR) i stopnia rozgałęzienia korzeni (BRA), wariancji których była głównie związana z efektami SCA. W przypadku niektórych cech, a zwłaszcza suchej masy korzeni (RDM), stosunku R : S i specyficznej długości korzeni (SRL) w warunkach suszy, zanotowano indukowany stresem wzrost proporcji GCA/SCA. Zastosowane niedobory wody i azotu na ogół nie wpływały na znak i zakres efektów GCA, ale istotność takich interakcji GCA- typ podłoża stwierdzono dla TLR i długości korzeni bocznych. Rzadziej notowane interakcje SCA-typ podłoża dotyczyły głównie TLR, a w mniejszym stopniu - stosunku R : S i długości korzeni bocznych. Analiza genetycznych komponentów wariancji wykazała, że efekty addytywnego działania genów miały decydujące znaczenie dla długości korzeni bocznych typy L i TLR, natomiast nieaddytywne działanie genów - dla RDM, SRL i BRA. Odziedziczalność w wąskim sensie większości cech korzeni była bardzo niska (0,01-0,34) i tylko TLR oraz długość korzeni bocznych typy L okazały się cechami o wyższej odziedziczalności (0,27-0,59 i 0,36-0,82). Ten znaczący udział nieaddytywnego działania genów może utrudniać selekcję zmierzającą do poprawy sposobu ukorzeniania się wśród mieszańcowego potomstwa badanej kolekcji pszenicy ozimej.
Zbadano wpływ różnych stężeń Actisilu podczas procesu ukorzeniania na jakość ukorzenionych sadzonek jałowca nadbrzeżnego (Juniperus conferta) ‘Schlagier’ oraz jałowca łuskowatego (Juniperus squamata) ‘Blue Star’. Doświadczenie potwierdziło korzystny wpływ preparatu Actisil na jakość ukorzenionych sadzonek jałowca nadbrzeżnego (Juniperus conferta) ‘Schlagier’ oraz jałowca łuskowatego (Juniperus squamata) ‘Blue Star’, wyrażoną liczbą i długością korzeni oraz wysokością sadzonek. Najkorzystniejszy wpływ na jakość ukorzenionych sadzonek, niezależnie od taksonu, miało zastosowanie Actisilu w stężeniu 0,1%.
Germination capacity, length of roots and seedlings and air-dry matter of plants of soybean, cucumber, buskwheat, winter wheat and white mustard were estimated in four soil material: bare soil and grass-covered soil from a side-space of roads with heavy traffic, soil from a farming field and washed, ca1cinated sand (pure sand). Highest germination capacity of investigated plants was found on pure sand. Seedlings germinated on soil from the grassy side space of the street had longer aboveground parts in comparison with those germinating on other soil material. Significantly smaller length of aboveground parts of seedlings were found on the object with washed and ca1cinated sand. On the pure sand, plant seedlings formed higher air-dry matter in comparison with the soil from a farming field. Independently of soil material, soybean and winter wheat seedlings formed the longest roots, aboveground parts and highest content of air-dry matter. On the soil from the grassy side space of the street roots of seedlings were significantly longer than roots of seedlings germinated on soil from a farming field. Greater content of some heavy metals in soil from side space of the street had no influence on germination capacity and investigated morphological characters of tested plants.
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