UNIVERSITÁ DEGLI STUDI DI CAGLIARI Scuola di Dottorato in Ingegneria e Scienze per l’ambiente e il territorio Corso di Dottorato in Botanica Ambientale e Applicata Ciclo XXVIII Comparative studies on the Silene mollissima aggregate (Caryophyllaceae) BIO/03 Coordinatore dottorato: Tesi presentata da: Prof. Gianluigi Bacchetta Valentina Murru Tutor: Prof. Gianluigi Bacchetta Co-tutors: Prof. Emmanuele Farris Dott. Andrea Santo Dott. Oscar Grillo Prof.ssa Marzia Boi Esame finale anno accademico 2015 – 2016 Tesi discussa nella sessione d’esame marzo – aprile 2017 Bene, vediamo un po’ come fiorisci, come ti apri, di che colore hai i petali, quanti pistilli hai, che trucchi usi per spargere il tuo polline e ripeterti, se hai fioritura languida o violenta, che portamento prendi, dove inclini, nel morire infradici o insecchisci, avanti su, io guardo, tu fiorisci. Da Poesie, Patrizia Cavalli 1999 INDEX Abstract .................................................................................................................................. 7 GENERAL INTRODUCTION .............................................................................................. 9 Biodiversity and endemism in the Mediterranean ..................................................... 9 The Silene mollissima aggregate .............................................................................. 11 Topics under study ............................................................................................................... 15 The importance of quantitative studies of seed characters ...................................... 15 Seed germination and seedling growth, two critical phases of plants life cycle ...... 16 The ecological niche and habitat specialisation ....................................................... 17 Aims ..................................................................................................................................... 19 References ............................................................................................................................ 20 CHAPTER I ......................................................................................................................... 32 Abstract ................................................................................................................................ 32 Introduction .......................................................................................................................... 33 Material and methods ........................................................................................................... 35 Seed lot details ......................................................................................................... 35 Image analysis .......................................................................................................... 35 Statistical analysis ................................................................................................................ 38 Results .................................................................................................................................. 42 Discussion ............................................................................................................................ 49 Conclusion ........................................................................................................................... 50 References ............................................................................................................................ 50 CHAPTER II ........................................................................................................................ 57 Abstract ................................................................................................................................ 57 Introduction .......................................................................................................................... 58 Materials and Methods ......................................................................................................... 59 Study species ............................................................................................................ 59 Seed lot details ......................................................................................................... 60 Germination tests ..................................................................................................... 60 Data analysis ........................................................................................................................ 61 Results .................................................................................................................................. 62 Effect of light on seed germination .......................................................................... 62 Effect of temperature and inter-population variability in seed germination ............ 62 NaCl and recovery on seed germination .................................................................. 63 Svel2 ........................................................................................................ 63 Svel3 ........................................................................................................ 64 Sich1 ........................................................................................................ 65 Sbad1 ....................................................................................................... 65 Effect of KNO3 on seed germination under salinity ................................................ 66 Effect of KNO3 under salinity on recovery .............................................................. 67 Discussion ............................................................................................................................ 68 References ............................................................................................................................ 70 CHAPTER III ...................................................................................................................... 75 Abstract ................................................................................................................................ 75 Introduction .......................................................................................................................... 76 Materials and Methods ......................................................................................................... 77 Study species and seed lot details ............................................................................ 77 Germination tests and seedling growth .................................................................... 78 Data analysis ........................................................................................................................ 79 Results .................................................................................................................................. 79 Mean seed weight and seed germination.................................................................. 79 NaCl effects and recovery ........................................................................................ 81 Silene mollissima ..................................................................................... 81 Silene hifacensis....................................................................................... 81 Discussion ............................................................................................................................ 84 Conclusions .......................................................................................................................... 86 References ............................................................................................................................ 86 CHAPTER IV ...................................................................................................................... 91 Abstract ................................................................................................................................ 91 Introduction .......................................................................................................................... 92 Materials and methods ......................................................................................................... 94 Study species ............................................................................................................ 94 Sampling design ....................................................................................................... 94 Response variables ................................................................................................... 95 Data analysis ........................................................................................................................ 97 Results .................................................................................................................................. 98 Abiotic factors .......................................................................................................... 98 Plot localization ....................................................................................... 98 Substrate .................................................................................................. 98 Biotic factors 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