8 research outputs found

    Multitraits evaluation of Pakistani ecotypes of berseem clover (Trifolium alexandrinum L.) under full-irrigation and water restriction conditions

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    Berseem clover (Trifolium alexandrinum L.) is an important forage crop in Pakistan and many ecotypes are grown across the country. Its yield is however frequently affected by insufficient irrigation due to unavailability of water. In the present study, twenty Pakistani ecotypes of berseem clover have been evaluated in lysimeters under full irrigation and water restriction conditions. In the full irrigation treatment soil humidity was maintained at field capacity, while in the water restriction treatment water was only supplied after severe wilting and to maintain humidity in the deep profile of the soil. Assessed traits included forage yield, calculated as the sum of the biomass harvested at 70 and 110 DA days after emergence, and morpho-physiological traits. Significant effects of water restriction were noted on yield, leaf gas exchange parameters, canopy temperature and osmotic adjustment. Most morpho-physiological traits had higher broad sense heritability than forage yield, both under full irrigation and water restriction conditions. Water restriction increased genetic and phenotypic variability and heritability of most traits under study. Under these conditions forage yield was positively associated to leaf temperature and recovery rate index and, under full irrigation, to net photosynthetic rate, canopy depression temperature and leaf area. The possible use of these traits as indirect selection criteria in berseem clover breeding programs is discussed. Some ecotypes with favorable traits such as high forage yield potential, good adaptation to water restriction and aptitude to multiple harvesting have also been identified

    A possibility of using the GGE biplot method to evaluate the state of and risks for Alopecuretum pratensis assotiation described in the Bug Ravine Landscape Park

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    Zesp贸艂 Alopecuretum pratensis (Regel 1925) Steffen 1931, wyst臋puj膮cy na terenie Parku Krajobrazowego "Podlaski Prze艂om Bugu", scharakteryzowano na podstawie 50 zdj臋膰 fitosocjologicznych, wykonanych metod膮 Brauna-Blanqueta. Ka偶de zdj臋cie opisano wzgl臋dnym pokryciem gatunk贸w: charakterystycznych dla klasy; charakterystycznych dla siedlisk wilgotniejszych lub siedlisk suchszych; synantropijnych oraz drzew i krzew贸w. Obliczono r贸wnie偶 nast臋puj膮ce wska藕niki Ellenberga: L - wska藕nik 艣wietlny, F - uwilgotnienia, R - odczynu gleby, N - zawarto艣ci azotu w glebie. Parametry te syntetycznie opisano metod膮 GGE biplot (ang. "Genotype and Genotype-by-Environment interaction effects"). Wykres typu biplot umo偶liwi艂 wytypowanie grupy niezaburzonych p艂at贸w zespo艂u Alopecuretum pratensis oraz p艂at贸w zaburzonych. Te ostatnie to albo fitocenozy wyst臋puj膮ce w siedliskach przesuszonych, w kt贸rych odnotowano r贸wnocze艣nie zwi臋kszony udzia艂 gatunk贸w synantropijnych, albo fitocenozy zlokalizowane w siedliskach wyra藕nie wilgotniejszych. Wi臋kszo艣膰 p艂at贸w zespo艂u Alopecuretum pratensis, zanotowanych na terenie Parku "Podlaski Prze艂om Bugu", wykszta艂ci艂a si臋 w warunkach siedliskowych zbli偶onych do optymalnych dla tego syntaksonu i zosta艂a zaliczona do postaci niezaburzonej, co 艣wiadczy o jego dobrej kondycji. Metoda GGE biplot okaza艂a si臋 przydatna do oceny stanu zespo艂u Alopecuretum pratensis oraz okre艣lenia kierunk贸w jego zmian.The Alopecuretum pratensis association (Regel 1925) Steffen 1931 in the Bug Ravine Landscape Park was described by 50 relev膷s with the use of Braun-Blanquet method. The aim of this study was to define the conditions and symptoms of degeneration of Alopecuretum pratensis. Each of the relev膷s was described by the relative cover of: characteristic species of Molinio-Arrhenatheretea class, characteristic species of wetter and drier habitats, synanthropic species, tree and shrub species. The Ellenberg indicators (L - light, F - moisture, R - soil pH, N - soil nitrogen) were also calculated. Above mentioned parameters were described synthetically by the GGE biplot method (Genotype and Genotype-by-environment interaction effects). The graph designated the group of undisturbed and disturbed phytocenoses of Alopecuretum pratensis. The disturbed phytocoenosis were often located in drier habitats or in markedly wetter sites. In the first case it was associated with greater participation of synanthropic species. Summing up, most of the described phytocoenoses of Alopecuretum pratenis developed in conditions close to the optimal for that syntaxon and were classified as undisturbed, which indicated their good condition in the Bug Ravine Landscape Park. Selection of appropriate parameters of examined plant community allowed the use of the GGE biplot method for assessing the state of Alopecuretum pratensis and determining the directions of its change

    Effects of mowing cessation on Molinietum caerulae meadow vegetation

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    Badania przeprowadzono w 2010 r. w 艢rodkowym Basenie Biebrzy w Biebrza艅skim Parku Narodowym. W celu okre艣lenia wp艂ywu zaprzestania koszenia na ro艣linno艣膰, na obiekcie 艂膮kowym Grz臋dy wytyczono dwa transekty - jeden w cz臋艣ci niekoszonej od 7 lat, drugi - w cz臋艣ci sporadycznie koszonej (raz na 2-4 lata). W ramach transekt贸w wykonano 艂膮cznie 23 zdj臋cia fitosocjologiczne metod膮 Brauna-Blanqueta. Obliczono wska藕niki Elleneberga: F - uwilgotnienia, N - zawarto艣ci azotu w glebie i R - odczynu gleby. Oceniono r贸偶norodno艣膰 gatunkow膮 zbiorowisk na podstawie: 艂膮cznej liczby gatunk贸w w transekcie, 艣redniej liczby gatunk贸w przypadaj膮cej na zdj臋cie fitosocjologiczne oraz obliczaj膮c wska藕nik r贸偶norodno艣ci gatunkowej Shannona-Wienera dla transekt贸w. Warto艣膰 u偶ytkow膮 zbiorowisk oceniono na podstawie LWU Filipka i zadarnienia. Stwierdzono, 偶e sk艂ad gatunkowy zbiorowisk w obu transektach jest podobny, jednak wyra藕nie r贸偶ni si臋 proporcjami. Na ca艂ym obiekcie dominuj膮 fitocenozy zespo艂u Molinietum caerulae W. Koch 1926 (klasa Molinio-Arrhenatheretea R. Tx. 1937). W cz臋艣ci, na kt贸rej przed 7 laty zaprzestano koszenia, w p艂atach zaznacza si臋 wyra藕ny podrost drzew: Salix cinerea L., Salix repens subsp. rosmarinifolia (L.) Hartm. i Betula pubescens Ehrh., co 艣wiadczy o post臋puj膮cej sukcesji wt贸rnej. W por贸wnaniu z obszarem sporadycznie koszonym wi臋ksza jest 艣rednia wysoko艣膰 ro艣lin, natomiast mniejsze - zadarnienie. Na obszarze koszonym udzia艂 gatunk贸w drzewiastych jest znikomy. Z wi臋ksz膮 ilo艣ciowo艣ci膮 wyst臋puje tu Carex panicea L. i Carex buxbaumii Wahlenb. Zaprzestanie u偶ytkowania spowodowa艂o wzrost 艂膮cznej liczby gatunk贸w w transekcie i 艣redniej liczby gatunk贸w w zdj臋ciu, ale zmniejszenie warto艣ci wska藕nika Shannona-Wienera. Warto艣膰 u偶ytkow膮 ro艣linno艣ci obu badanych transekt贸w oceniono jako bardzo s艂ab膮.The study was carried out in the year 2010 in the Middle Basin of the Biebrza River in the Biebrza National Park. The aim was to find out if the cessation of mowing could have changed some parameters of the existing vegetation. And if yes - what kind of changes could be noted. The examined phytocoenoses were described by 23 relev膷s made with the BRAUN-BLANQUET method (1964). Eleven of them were made within the transect where vegetation had been mowed every 2-4 years, and the other 12 - in the transect, where vegetation had not been mowed for the previous 7 years. Species diversity was assessed upon: species composition of each community, their syntaxonomic structure, species richness, floristic diversity calculated using the SHANNON-WIENER index (H') and site conditions estimated with the ELLENBERG phytoindication method (1992]. The utilization value based on the fodder value score (FVS) defined by FILIPEK (1973) and sod cover were also estimated. It was found that species composition in both transects was very similar, however, the proportion of some species and syntaxonomic groups of species was different. Generally, the whole examined area was covered by the phytocoenoses of Molinetum caerulae association. In the not mowed part the clear symptoms of secondary succession were noticed. Young trees and shrubs, mainly Salix cinerea, Salix repens subspec. rosmarinifolia and Betula pubescens, appeared in vegetation units. In comparison to the mowed area the total number of species in the phytosociological relev茅 and mean height of plants were higher, whereas the sod cover was lower. In the mowed area the mean cover of trees and shrubs was negligible. Carex panicea and Carex buxbaumii were numerous there. Other results of the abandonment of utilization were: a higher species richness and a lower value of Shannon-Wiener index. The utilisation value of vegetation in both examined transects was very poor
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