کشت و چرخۀ زندگی زیرۀ استوانه‌ای ‏‎(bunium ‎cylindricum)‎‏: تکوین اندام‌های مختلف

با وجود گزارش‌های متعدد از رویش سخت bunium persicum، مطالعۀ منتشرشده‌ای در زمینۀ b. cylindricum دیده نشد. اگرچه میزان اسانس و فنلیک‌ها در زیرۀ سیاه زیاد است، در b. cylindricum نیز درخور توجه‌اند. تکوین گیاه از کشت دانه تا تولید دانه، سه تا چهار سال طول می‌کشد و شامل تشکیل برگ‌های لپه‌ای، یک برگ یک- یا دو- بار شانه‌ای، یک برگ سه-‌ بار شانه‌ای و تعدادی برگ سه- ‌بار شانه‌ای (2≤) طوقه‌ای (روزت) در سال چهارم است. طی نمو، بنه (کورم) بزرگ و در سال گل‌دهی، همراه با تشکیل برگ‌های طوقه‌ای با دمبرگ بلند، ساقه و اجزای آن نیز تشکیل می‌‌شوند و تعداد برگ‌ها و ساقه‌های گل‌دهنده به اندازۀ بنه (کورم) بستگی دارد. گل‌ها بدون کاسبرگ با گلبرگ‌های نازک و پیش‌پرچمی هستند. تاپی ترشحی، گرده کشیده، کوچک، تخم‌مرغی با تزئینات رگه‌دار (striate)، regulate یا حدواسط بودند. تخمدان دو برچه‌ای، زیرین با تمکن راسی که دو میوه فندقه استوانه‌ای- خطی از محل کارپوفور بسوی سر باز می‌شوند.

cultivation and life cycle of bunium cylindricum: development of ‎different organs

despite numerous reports on hard germination and growth of bunium persicum, there is no published study on b. cylindricum. although the amount of essential oils and phenolics is high in b. persicum, they are significant in b. cylindricum too. plant development from seed cultivation to seed production took 3-4 years including the formation of cotyledon leaves, a uni- or bi-pinnate leaf, one tri-pinnate leaf, and two or more tri-pinnate leaves (rosette) with long petiole in the fourth year. during development, corm size increases, and in flowering years, along with rosette leaf formation, flowering stems are also formed and their number depends on corm size. flowers were protandrous, without calyx with thin petals containing secretory epidermis. tapetum is the secretory type and pollen is tricolporate, prolate (p/e 1.7), small size (24µm), ovate with striate-regulated sculpture. the ovary is two-carpellate, inferior with apical placentation which its two cylindric-linear mericarps are separated acropetally from the carpophore at maturity. introductionbunium (apiaceae) has about 14-17 species in iran. secondary metabolites of some species of bunium, especially b. persicum, have been studied. the antimicrobial, antioxidant, anti-inflammatory, anti-diabetic, and other therapeutic properties of their essential oils have been reported. the presence of numerous essential oils in b. cylindricum indicates its medicinal importance. in some cases, the same names are used for different species, or different names are used for different populations of one species. in addition, some people mix fruits (seeds) of different species of bunium and sell them as b. persicum in the markets. therefore, the correct identification of species and their cultivation is important, particularly for species that are marketed. there are several reports about hard germination and cultivation and growth problems of b. persicum. however, there is no published study on the cultivation, life cycle, and vegetative and reproductive structures of b. cylindricum, except general descriptions in plant flora’s books. kazemivash et al. (2020) reported that in b. persicum, the tapetum layer is secretory type; pollen grains are ovate and bi-porate; gynoecium is two-carpellate with lower ovary and schizocarpic fruits. apiaceae pollen has been divided into five types: sub-rhomboidal (p/e=1–1.5), sub-circular (1–1.5), oval (1.5–2), sub-rectangular (2), and equatorially constricted (≥ 2). fruit is a dry schizocarp composed of 2 mericarps that split apart at maturity acropetally. mericarps have secretory ducts that cause good aroma and flavor in many plants of this family law. in the present study, species cultivation and seed formation were done for the first time. further, the structure and development of vegetative and reproductive structures were studied and investigated. materials and methodsthe ripe seeds (mericarps) of b. cylindricum were collected from sarduiyeh, kerman province, iran. they are cultivated in petri dishes, pots, and in plant habitat in a garden. seed germination, the life cycle of the species, and different organ formation were studied until flower and seed/fruit formation. fresh structures (corms, leaves, inflorescences, flowers, and fruits) in different developmental stages were studied and photographed using stereo and light microscopes or the naked eye. the pollen structure, p/e ratio, and pollen sculpture were studied using light and scanning electron microscopy (sem). fruit size and the number of fruits in the umbellate were surveyed too. for anatomical studies, fresh flowers were fixed in faa (formaldehyde: acetic acid: 70% ethanol, 5:5:90, v/v/v) for 24 h, washed with distilled water 4 times (each time for 5 min), dehydrated in 30%, 50%, 70%, 80%, and 100% ethanol series and embedded in paraffin. then, 5 μm sections were cut by a rotary microtome (micro-tec, germany), put on glass slides, stained by hematoxylin and eosin, observed by a light microscope, and photographed. the mean of seed germination, the polar and equatorial axis of pollen, and their ratio (p/e), as well as the average length of umbel rays and fruit, were measured. results and discussionbunium is one of the medicinal plants with high economic and export value. there are no published studies on the cultivation, seed germination, and development of b. cylindricum. the study of the life cycle of b. cylindricum showed that the species produces flowers and fruits (seeds) 3-4 years after cultivation. in the first year, cotyledon leaves and a small underground part (corm) are formed, and its size increases during the following years producing compound rosette leaves and shoots. after cotyledon leaves, a uni- or bi-pinnate compound leaf with long petiole, then in the next year one tri-pinnate leaf and finally with increasing tuber size, tri-pinnate leaves (≥2) and flowering shoots are formed. there are several studies indicating hard plantation and germination of bunium using different treatments for breaking dormancy without studying the next developmental stages till flowering. the present study optimized cultivation, seed germination, and flower and seed production in b. persicum for the first time. the abundance of flowers in broad umbellate inflorescences and secretory structures of pistils and petals help to attract pollinators confirming linder (1998) who reported the effective role of inflorescences in pollination. flowers were pentamerous, protandrous, without calyx with thin petals containing secretory epidermis. tapetum was secretory type and pollen grains were tricolporate, prolate (p/e 1.7), small size (24µm), ovate with striate-regulated sculpture according to punt et al. (2007), cerceau-larrival and roland-heydacker (2013), başer et al. (2021), and kadluczka et al. (2022). studies in b. persicum indicated secretory tapetum and bi-porate. the gynoecium is bicarpelate producing a schizocarp fruit in which its two mericarps are separated at maturity. its distinctive flavors are due to fruit secretory cavities.  conclusionthere are several studies reporting hard plantation and seed germination of bunium genus, especially b. persicum. in this study, cultivation, seed germination, and seed production of b. cylindricum were optimized. seed germination was ≥ 90% and germinated seedlings produced fruits (seed) in the fourth year. flowers were pentamerous, protandrous, without calyx with thin petals containing secretory epidermis. pollen grains were tricolporate, prolate, small-sized, and ovate with striate-regulated sculpture. the fruit is a schizocarp consisting of two fused carpels that separate at maturity into two mericarps, each containing a single seed. secretory ducts are distributed in the fruit pericarp.