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PIXE analysis was applied to study alteration of mineral composition (Al, P, K, and Cl) of alfalfa root-tip exposed to low pH or aluminum stress. These minerals were detectable using one or two pieces of root-tips. Short-term (within 4 h) decreases in K/P and Cl/P ratios were observed under low pH and aluminum stress conditions. However, degree of the decrease was not same. Differences in toxic effects of low pH and Al on the root-tip of alfalfa are discussed.

Elemental composition of living cells and tissues reflects their physiological function and status. However, it has been difficult to know in-situ elemental distribution by conventional analytical methods. In-air PIXE seems suitable for surface analysis of living cells and tissues because any treatment (e.g. freeze drying, digestion) is not required before and during measurement. We applied Via (vertical-beam in-air) PIXE to surface analysis of plant roots exposed to aluminum (Al). Aluminum stress is a major factor that limits elongation of plant roots in acid soils. We previously reported decrease in atomic ratio of potassium to phosphorus (K/P ratio) of dried root-tip of alfalfa (Medicago sativa L.) under Al stress using in-vacuum PIXE. In Via PIXE, 5 to 7-minute irradiation by 3 MeV proton beams of 200 pA was sufficient to obtain X-ray spectra without drying root samples. Decrease in K/P ratio in surface cells of root-tips was observed by short-term (6-8 h) exposure of root to Al. Via PIXE is recognized as a powerful tool for in-situ surface analysis of plant material.

The present study was conducted to determine whether lyophilized aqueous extract of alfalfa, or Medicago sativa L. could exert antioxidant activity against carbon tetrachloride-induced oxidative stress and liver injury in rats. The hepatoprotective activity of alfalfa extract was determined by assessing the levels of serum transaminases, ALP, bilirubin and lipid profile. Further, the effect of the test substance on malondialdehyde (MDA), an end product of lipid peroxidation; antioxidant liver enzyme non-protein sulfhydryl (NP-SH); and total protein (TP) were also studied. Serum transaminase, ALP, bilirubin level, lipid profile and liver MDA were significantly elevated and the antioxidant status in liver NP-SH and TP contents were declined in animals treated with CCl₄ alone. Pretreatment with alfalfa and silymarin for three weeks prior to the administration of CCl₄ significantly prevented the increase in the serum levels of hepatic marker, LDL, VLDL levels enzymes and reduced oxidative stress indicated by elevated NP-SH and TP concentration. The histopathological examination of the livers also showed that the alfalfa extract reduced the incidence of liver lesions induced by CCl₄. The in vitro antioxidant assessment of alfalfa extract on DPPH and carotene-linoleic assays demonstrated a moderate antioxidant potential. Results suggest that the alfalfa extract possesses hepatoprotective and antioxidative stress properties possibly through its antioxidant phytochemical constituents and substantiates its use in various liver disorders as a hepatoprotector.

In terms of dehydrating test on alfalfa, 5HC-1 type of conservation herbage dryer by advanced technology such as steel wire-bed conveyer, waste hest retrieving, turning over in airflow and mixed drying was designed, manufactured and tested. This paper describes the design and test of concurrent-flow dryer for conservation of quality on the basis of the experiment. The drying process-flow, construction and drying parameters of the dryer are presented. This designed dryer is suitable for farm, pasture and livestock-raising. Quality of dried alfalfa is good. This dryer is more efficient and adaptable. The cost of dryer is lowered. So the extension and application of the 5HC-1 type of conservation herbage are helpful to accelerate development of intensive breeding.