Aluminum (Al) is one of the major factors adversely affects crop growth and productivity in acidic soils. In this study, the effect of Al on plants in soil was investigated by comparing the protein expression profiles of alfalfa roots exposed to Al stress treatment. Two-week-old alfalfa seedlings were exposed to Al stress treatment at pH 4.0. Total protein was extracted from alfalfa root tissue and analyzed by two-dimensional gel electrophoresis combined with MALDI-TOF/TOF mass spectrometry. A total of 45 proteins differentially expressed in Al stress-treated alfalfa root tissues were identified, of which 28 were up-regulated and 17 were down-regulated. Of the differentially expressed proteins, 7 representative proteins were further confirmed for transcript accumulation by RT-PCR analysis. The identified proteins were involved in several functional categories including disease/defense (24%), energy (22%), protein destination (9%), metabolism (7%), transcription (5%), secondary metabolism (4%), and ambiguous classification (29%). The identification of key candidate genes induced by Al in alfalfa roots will be useful to elucidate the molecular mechanisms of Al stress tolerance in alfalfa plants.

Acidic soil significantly reduces crop productivity mainly due to aluminum (Al) toxicity. Alfalfa (Medicago sativa L.) roots were exposed to aluminum stress (Al3 +) in calcium chloride (CaCl2) solution (pH4.5) and root growth, physiological and antioxidant enzyme responses were investigated. The root growth (length) was significantly inhibited after 48 h of aluminum stress imposition. Histochemical staining with hematoxylin indicated significant accumulation of aluminum in Al stress-treated root tissues. Histochemical assay were also performed to detect superoxide anion, hydrogen peroxide and lipid peroxidation, which were found to be more in root tissues treated with higher aluminum concentrations. The enzymatic activity of CAT, POD and GR in root tissues was slightly increased after Al stress treatment. The result suggests that Al stress alters root growth in alfalfa and induces reactive oxygen species (ROS) production, and demonstrates that antioxidant enzymes involved in detoxification of Al-mediated oxidative stress.

Research on alfalfa root morphology and health is very important in development of technology for efficient improvement and production of alfalfa. The objectives of this study were to evaluate the root morphology and health of two alfalfa varieties, Algonquin and Golden Queen, to determine relationships among root morphology traits and root health. Results from these analyses indicated t㏊t yield was 6.77-43.93 t/h㎡, total root length ranged from 215.17-708.89 ㎜, root surface area ranged from 93.61-717.06 ㎠, volume ranged from 3.24-57.72㎤. Results from these analyses indicated t㏊t root infestation score was the lowest averaged over age of alfalfa stand in Algonquin. Yield in 2-yr old stands was greater in Golden Queen compared to Algonquin.

알팔파 종자를 의 2,4-D를 첨가한 SH 배지에서 배양하여 캘러스를 유도하였으며, 캘러스를 SH 배지에 의 NAA와 의 kinetin을 첨가한 배지에서 28~30일간 배양하고, 의 2,4-D와 의 kinetin을 첨가한 배지에서 3~5일간 배양 후, 의 (와 의 proline을 첨가한 배지에서 21~25일간 배양하여 완전히 재분화된 식물체와 많은 수의 shoot를 얻었다. 알팔파의 재분화 과정에서 뿌리가 유도되는 효율을 높이기 위해, SH salt의

알팔파 (Medicago sativa L.)의 줄기부분을 절단하여, SH 배지에 IBA를 첨가한 농도별로 뿌리 유도 정도를 조사한 결과, IBA 농도를 1.0~1.5 mg/로 첨가한 처리구에서 뿌리 유도 정도가 70~75%로서 가장 좋았다. 캘러스로부터 shoot를 유도한 다음 줄기를 취하여 처리한 경우에는. 처리 10일째에 1/2 SH-0 배지에서 10개 (50%), SH-0 배지에서 10 (50%), SH-0.5IBA 배지에서 12개 (60%), S

Most parts of alfalfa plant have been reported to contain autotoxic substances that inhibit seed germination and early seedling growth, however, the chemical(s) is not still studied much. Effect of seed leachates of 'Vernal' alfalfa (Medicago sativa L.) was evaluated for inhibition of alfalfa germination and root growth through bioassay. Alfalfa seeds were extracted in 1 L deionized water for 1 h after soaking and the leachates caused to reduce root length of alfalfa significantly as the soaking time increased. Crude seeds at 4 g LL-1 exudated autotoxins that reduce significantly root length by 34 % compared to the control, when the seeds soaked in deionized water for 24 h. However, the extracts did not affect final germination as well as speed of germination. Extracts from ground seeds significantly reduced speed of germination (GT 50) and root length. The results indicate that release of autotoxic substances from seeds during seed imbibition was increased with increase of soaking time and seed amount, and that autotoxicity was more occurred in ground seeds than in crude seeds.