Evaluation Of Germplasm Resource Of Allium Obliquum L.

Allium obliquum L. is a perennial herb and also an early spring wild vegetable, distributing in the area of 50°N,85～95°E. It is one of the allium germplasm resources that distributed only in Xinjiang. There have no reports about domestic cultivation and biology characters domestically. The phenophase, foilage growth characteristics, nutrition factors, seed biology, reproduction biology and descriptors have been studied and established in order to provide a new vegetable resource, parent materials of allium vegetables, a system of methods for studying allium plants in Xinjiang, a basic work for domestication and information establishment of international allium germplasm resources, and promote the breeding work of allium vegetables and reasonable exploitation of allium resources in Xinjiang. The main results can be summarized as follows.(1)The phenophase has been observed for three years, the result shows that A. obliquum is a seedling vernalization and long-light plant which needs enough water supply and moderate light intensity in the growth period. The A. obliquum, which sprouts and grows fast in the early spring with summer dormancy to evade disadvantage environment condition, has strong cold tolerance and poor hot and drought tolerance. Besides, it has no requests for the soil fertility indicated from the growing phenomenon when cultivated in the resource garden.(2) After the analysis of A. obliquum foilage growth characteristics, the result indicates that the whole plant is available to eat, especially the flat fleshy foliage. The plant height and cauloid diameter of juvenile period has significant positive correlation with foliage numbers. The characters of foliage are strong, erect and fresh. Its vegetative period lasts 25～34 days and during reproduction period there is few new foliages observed. Therefore, the best detachable time is 30 days after foliage had unfolded. Enough water and fertility supplying and reasonable dense planting are necessary for nutrition accumulation and the maximum economic output.(3) The nutrition contents of carbohydrate, crude fibre, vitamin C, carotenoid and protein have been analyzed. The result shows that A. obliquum has full nutrition factors. The plants in vigorous vegetative growth period have moderate crude fibre content, high water content, and the vitamin C content is extremely higher than other allium vegetables. Plants in this growth period are suit for fresh eat. Plants at the primary period of bolting are more suitable for processing, because of the vitamin C and carotinoid contents decreased with the special pungent taste of alliums increased.(4) A. obliquum is a seed dispersal plant. The study of seed biology show that oboval seed with three edges weighted 0.21 g per 100 seeds, black and lackluster seed coat with nothing attached, white hilum slot-shaped, liner embryo winded in the endosperm and the micro-morphology of seed-coat has unusual characters for identify species and discuss relationship.After seed phenological studying, the range of optimal temperature for A. obliquum seeds germination is 15～20℃. It appears longer germination time, lower germination rate, out of order germination and poor seedling ability when seeds germinate at temperatures that higher than 25℃or lower than 15℃. Seeds germinate better in 15/25℃alternating temperature regimes than at constant temperatures. There have no significant stimulated or inhibited effects on the seeds germination by illumination. Sowing seed in the opening field in spring can satisfy the temperature and light requirement for germination. What's more, artificial alternating temperature treatment can speed up the germination and improve the seedling orders.Seeds of A. obliquum have non-deep physiological dormancy. Though stratification can break this dormancy, temperature takes an important role in the treatment. Cold stratification at 5℃needs more time for germination, while warm stratifications at 10/20℃,15/25℃and 20/30℃need shorter time for germination, but there is no differences in the seedling quality. However, treated at a lower temperature after warm stratification induce secondary dormancy. The poor penetrate and imbibition ability of seed coat results in the seed dormancy. There is no inhibitory substance found.The result of artificial aging treatment indicates that seeds of A. obliquum have storage potential. The life expectancy is over 2 years when stored at ambient temperature. The dormancy of seed coat and seed physiology is a protective mechanism for delaying aging. The aging treatment temperature and humidity have the effects on breaking the fresh seeds dormancy. Hydration-dehydration treatment can repair the membrane structure and improve the seeds vigor of the old seeds.The A. obliquum seeds have strong tolerance to saline-alkali soil and this tolerance relates to the salinity and saline compound. The soil salt and alkali just inhibit seeds germination, but this inhibition can be recovered by the eluviation of rain and snow. The harm degree of different single salts is NaCl> NaHSO4> Na2SO4 to seeds and NaHSO4> NaCl> Na2SO4 to seedling ability. The inhibition effect on seeds germination will enhance when increasing the mole ratio of Na2SO4 in the mixed saline-alkali solution. Low density of NaHCO3 can force seeds germination, but weaken the seedling ability.(5) Reproduction biology study indicates that A. obliquum is a cross-pollinated plant. The stigma becomes receptive when the six anthers had pollinated fully. The stigma receptivity gets to the highest when the corolla closed. The stigma receptivity decreased with the stigma wilting. The higher pollen vigor lasts 4 hours after pollinating, and then decreased extremely. Different bees as the pollinating medium are the important assurance for its reproduction success.(6) According to the IPGRI Allium descriptors,30 descriptors have been established in the aspects of collecting data, plant, inflorescence, fruit and seed.