Sēklu organiskā miera perioda veidi un tā pārtraukšana dažām Latvijas piekrastes augu sugām
Date
2009
Authors
Bodniece, Karīna
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Publisher
Latvijas Universitāte
Abstract
Organiskais miera periods (OMP) ir sēklām raksturīga īpatnība, kas ļauj tām ilgstoši saglabāt dzīvotspēju un uzdīgt dīgšanai piemērotākajā brīdi, kurā noteiktu vides faktoru kombinācija nodrošina dīgstu izdzīvošanu. Šī pētījuma mērķis bija pārbaudīt OMP esamību piecu Latvijas piekrastes augu sugu sēklām un noteikt tā piederību kādam organiskā miera perioda veidam. Pētījumā apskatītās sugas bija jūrmalas meldrs, ezera meldrs, smiltāja grīslis, biezlapainā sālsvirza un smiltāja neļķe.
Apskatītajām sugām novēroja atšķirīgu stratifikācijas un giberelskābes ietekmi uz sēklu dīgšanu, kā arī iespējamu sekundārā organiskā miera perioda iestāšanos dīgšanai nelabvēlīgu apstākļu ietekmē pēc tam, kad daļēji vai pilnībā tika pārtraukts primārais OMP. Vislielākais efekts abiem apstrādes paņēmieniem konstatēts smiltāja neļķei un kā OMP veids noteikts – fizioloģiskais. Arī smiltāja grīšļa un biezlapainās sālsvirzas dīgtspēja bija augsta. Mazāk efektīvas pētījumā izmantotās OMP pārtraukšanas metodes izrādījās jūrmalas un ezera meldra sēklām, kas neļāva skaidri noteikt OMP veidu un tā konkretizēšanai nepieciešami turpmāki pētījumi.
No iegūtajiem rezultātiem ir skaidrs, ka sēklu stratifikācija un uzbriedināšana nelielas koncentrācijas giberelskābes šķīdumos būtiski spēj palielināt sēklu dīgšanas ātrumu.
Seed dormacy is a seed specific property which allows them to save vitality for a long time period and germinate when environmental conditions are most appropriate for the species to spread. The aim of this study was to check the presence of seed dormancy and define its type in seeds of five coastal species of Latvia. Species used in this study were Scirpus maritimus, Scirpus lacustris, Carex arenaria, Dianthus arenarius and Honckenya peploides. During research different effects of cold stratification and gibberellic acid on germination of the tested species were noticed. In addition, after release of primary dormancy, in some species treatments possibly induced secondary dormancy. The highest germination rates, independently of seed dormancy breaking treatment, were stated for Dianthus arenarius and physiological dormancy was defined for this species. Germination rates for Carex arenaria and Honckenya peploides were also high. Dormancy breaking treatments for Scirpus maritimus and Scirpus lacustris turned out less effective and that prevented precise determination dormancy type. Further research has to be done. Study results show that seed cold stratification and treatment with low concentration gibberellic acid solutions significantly increase the speed of seed germination.
Seed dormacy is a seed specific property which allows them to save vitality for a long time period and germinate when environmental conditions are most appropriate for the species to spread. The aim of this study was to check the presence of seed dormancy and define its type in seeds of five coastal species of Latvia. Species used in this study were Scirpus maritimus, Scirpus lacustris, Carex arenaria, Dianthus arenarius and Honckenya peploides. During research different effects of cold stratification and gibberellic acid on germination of the tested species were noticed. In addition, after release of primary dormancy, in some species treatments possibly induced secondary dormancy. The highest germination rates, independently of seed dormancy breaking treatment, were stated for Dianthus arenarius and physiological dormancy was defined for this species. Germination rates for Carex arenaria and Honckenya peploides were also high. Dormancy breaking treatments for Scirpus maritimus and Scirpus lacustris turned out less effective and that prevented precise determination dormancy type. Further research has to be done. Study results show that seed cold stratification and treatment with low concentration gibberellic acid solutions significantly increase the speed of seed germination.
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Bioloģija