Embryoid formation in alfalfa cell suspension cultures from different plants

Summary Cell suspension cultures were initiated from shoot tips of nine plants of alfalfa. Our results indicated that considerably different nutritional conditions were required to induce embryogenesis in the cell cultures derived from these plants. By proper adjustment of the hormone level and mineral salt concentration it was possible to induce embryogenesis in all of the nine cultures tested. The embryoids from seven of the nine cultures were able to develop into plants.     

Resistant Host Responses to Ten California Populations of Meloidogyne incognita

Resistant and susceptible cultivars of tomato, lima beans, cotton, and alfalfa were tested with 10 populations of Meloidogyne incognita from different California locations. Nine of the populations differed in aggressiveness on the nine cultivars tested. Two populations were especially aggressive toward resistant tomato cultivars.     

Detection and Identification of Two Phytoplasmas (16SrIII‐B and 16SrXII‐A) From Alfalfa (Medicago sativa) in Serbia

Plants of alfalfa (Medicago sativa) exhibiting general stunting, proliferation and phyllody associated with leaf yellowing and reddening were observed in three localities of Central Serbia. Phytoplasma strains belonging to 16SrIII‐B and 16SrXII‐A groups were detected and identified by RFLP and sequence analysis of 16S rDNA. Stolbur phytoplasma tuf gene RFLP analysis showed the presence of the TufAY‐b‐type phytoplasma subgroup in 80% of symptomatic samples. This is the first report of 16SrIII‐B and 16SrXII‐A phytoplasma groups affecting alfalfa in Serbia.     

A simple and effective method for isolating RNA from alfalfa pollen

Extraction of RNA from alfalfa pollen using conventional grinding devices resulted in low yields of degraded RNA; degradation appeared to be related to the length of time required to break open the pollen grains with such devices. A glass syringe was modified to provide the restricted, shearing environment necessary for rapidly rupturing this type of tissue. This apparatus would be useful for extracting a variety of molecules from pollen of any species, but is particularly valuable for species which produce low amounts of relatively small pollen grains.