March 26, 2008
Order ARASYSTEM Well Before You Need It

One consequence of the relentless devaluation of the dollar this past year, has been that LEHLE SEEDS has been maintaining lower levels of ARASYSTEM  inventory available for sale.  We are not particularly happy operating this way and are hopeful that it is a temporary situation.  Thus far, we have been fairly lucky, but the potential is there to disappoint significantly on the expected time of an ARASYSTEM delivery.   As it is not in our interest to inconvenience our customers,  we ask that customers kindly  place your ARASYSTEM orders well in advance - one to two months in advance.  This will help us deliver your ARASYSTEM on time, when you need it..

Fred Lehle, Ph.D.

January 18, 2008 (Original posting April 3, 2007)
Early Adopters Really Like Our ArabiSifter Floral Sleeves  

LEHLE SEEDS is now offering a new innovation for flower containment and seed harvest of our own design.  We call it the ArabiSifter and have assigned it cat. no. SNS-01. Early users have reported to us that they really like using the ArabiSifter.  They also like the fact that the ArabiSifter is very affordable and makes seed cleaning during harvest much more convenient, since with the ArabiSifter, the sieve is disposable.

So what is the ArabiSifter?  The ArabiSifter is simply a flared, light-weight, transparent plastic floral sleeve that encloses an Arabidopsis plant or plants growing in either a round or square pot.  Similar to existing tubular enclosures, the ArabiSifter 1) provides support for your flowers and 2) acts as a physical barrier to prevent the flowers in one pot from entangling with those of another (Figure 1).

The ArabiSifter, however, goes a step further.  First, the unique design of the ArabiSifter is that each ArabiSifter is covered with thousands of small holes. Relative to a rigid, solid-walled tube, we believe the holes in the ArabiSifter as well as its flared top will facilitate better air and moisture circulation and better heat and ethylene dissipation in confined spaces such as in a growth room.  

But the real purpose of the holes in the ArabiSifter is to simplify seed cleaning and save time and labor at seed harvest.  The ArabiSifter accomplishes this by serving as a disposable seed sieve as follows.  The mature plant and enclosing ArabiSifter is cut from the pot at the base, and both open ends are stapled closed.  The plant material enclosed in the ArabiSifter is then gently shaken by hand over a large sheet of paper.  The shattered seeds fall through the holes which act to sieve the seeds from the retained plant residue (Figure 2).  Since each plant has its own disposable ArabiSifter sieve,  you save time by not having to clean and dry a permanent hand sieve between separate harvests.  If you have ever harvested a lot of separate Arabidopsis plants, you know cleaning a hand sieve between harvests is a major bottleneck.

As you know, rendering transgenic plant residue harmless before disposal is essential for regulatory compliance.  For its part, the ArabiSifter simplifies this process considerably.  Simply wrap your used ArabiSifters en masse with enclosed plant residue in folded aluminum foil and autoclave on the 10 min "wrap" cycle.  Place this in the trash and this portion of your transgenic waste disposal problem is complete.  Compliance this convenient is spelled A-r-a-b-i-S-i-f-t-e-r.

So what are some factors affecting sieving efficiency with the ArabiSifter?  First, your plants should be mature and ready for harvest.  This means the siliques are dry, have no green color left and readily shatter their seeds when disturbed.  Under these conditions, sieving efficiency with the ArabiSifter is greater the gentler the shaking.  More aggressive shaking and crushing of plant residue will cause more chaff and fines to end up in the seed fraction, just like with a metal hand sieve. Regardless of your method or technique, one pass through the ArabiSifter will free your seeds from the bulk of the plant residue.  

The ArabiSifter is sold in convenient, stacks of 50 sleeves that you tear-off one at a time. The flat dimensions are 3.75" (9.53 cm; bottom edge) x 14" ( 35.56 cm; top edge) x 21.5" (54.61 cm; length). Simply cut the bottom edge of the ArabiSifter to fit your existing pot.  Trim the top edge to fit the height of your lighting system. The ArabiSifter fits a wide range of both round and square plots, from a 3" (7.6 cm) diameter round pot to our recommended square ArabiPot  (shown in Figures 1 and 3).  

Order Cat. no. SNS-01
 ArabiSifter 
Floral Sleeves for Arabidopsis

To place an order

Call 1-800-881-3945
 (Toll-free in USA)

Fax 1-512-388-3974

April 3, 2007

New Product - The ArabiPot
Your Arabidopsis Roots Will Thank You.

The relative low air-porosity of Arabidopsis media, composed of  perlite and peat moss with variable amounts of  vermiculite, has been rated fine (Passioura 2006).  As such, Arabidopsis roots, growing in the bottom 50-70 mm of medium, regardless of pot depth, are repeatedly subjected to severely reduced oxygen levels following routine subirrigation (Passioura 2006).  While it is common to grow Arabidopsis in containers as short as 2.25" (57 mm) in height, subirrigation under such conditions requires close monitoring to avoid prolonged root water-logging which quickly slows root tissue and can stunt whole Arabidopsis plant growth.

Fortunately, there is a simple solution to avoid water-logging and hypoxia in Arabidopsis roots and that is to grow Arabidopsis plants in a deeper pot and one holding as much medium volume as possible. This is standard horticultural practice for many potted plants (Pasian 2007). 

In a deeper pot, a greater percentage of the medium near the surface will always have more pores filled with air than those in the bottom of the pot.  This provides a top region where roots can grow without the danger of hypoxia.  Given the fine porosity of common Arabidopsis media, recent  research (Passioura 2006) suggests that a pot would need to be at least 120 mm deep to guard against the possibility of ever accidentally inducing complete hypoxic conditions throughout all a pot's growth medium.

Though counter-intuitive, square pots of the same footprint contain significantly more volume than round pots.  More medium volume increases the number of pores which improves root aeration.    Thus, given the fine air-porosity rating of Arabidopsis media, a taller square pot is much better for growth than a short round pot.

We are pleased to announce that we now offer such a pot, one both tall and square, which we call the ArabiPot (Figure 3)..  The ArabiPot is a 3.5" x 3.5" (89 x 89 mm) square pot which is a full 5" (127 mm) in depth.  We offer the ArabiPot combined with subirrigation trays as cat. no. PTA-10 ArabiPots and Trays.  The PTA-10 box includes 180 ArabiPots and 10 subirrigation trays.

The ArabiPot  works with ARASYSTEM Aracons as well as our cat. no. SNS-01 ArabiSifter floral sleeves.  We recommend using the ArabiPot with either our cat. no. PM-15-13 AIS or cat. no. PM-25-13 PMP growing media for best results.  A single ArabiPot holds about 0.66 L of growing medium.  A box of PM-15-13 (or PM-25-13, 13 dry gallons each) will fill about 74 individual ArabiPots or 4 trays of ArabiPots (18 ArabiPots per tray).  Thus, you will need about 2.5 boxes of either growing media to fill the 180 ArabiPots of cat. no. PTA-10. 
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Pasian, CC (1997) The Ohio State University Fact Sheet HYG-1251-97 Physical Characteristics of Growing Mixes. OSU Horticulture and Crop Science  http://tinyurl.com/2cehv8

Passioura JB (2006) The perils of pot experiments.  Func. Plant Biol.33:1075-1079  

Order Cat. no. PTA-10
 ArabiPot & Trays for Arabidopsis

To place an order

Call 1-800-881-3945
 (Toll-free in USA)

Fax 1-512-388-3974