Tetrazolium test procedure for Sorghum bicolor x S. sudanense

Transcription

1 Tetrazolium test procedure for Sorghum bicolor x S. sudanense Topics: TZ Test according to ISTA Rules (2004) TZ Test according to ISTA Working Sheets on Tetrazolium Testing 2003 TZ Test according to Handbook On Tetrazolium Testing, ISTA (Moore R.) TZ Test according to Tetrazolium Testing Handbook, AOSA 2000

2 This methodology: Was proposed by the Working Group 4, leaded by, in charge of studying Tetrazolium methods in Agricultural Species within the ISTA Tetrazolium Committee from 1995 up to 2001 Was voted in the ISTA International Congress in 2001, in Angers, France Was effective in the ISTA Rules from 1 st January 2002

3 Premoistening: Soak in water, 18 hours, at a low temperature (7ºC)

4 Preparation before staining: longitudinal cut through the middle of the embryonic axis and 1/4 of the length of the endosperm

5 Staining at 30ºC: Using a solution of 1.0% tetrazolium chloride For three hours

6 Evaluation guide Scutellum Leaf Root cap Coleoptile Shoot apex Radicle Coleorhiza

7 VIABLE SEEDS

8 NON-VIABLE SEEDS

9 COMPARISON PREPARATION STEP ISTA Rules 2004 ISTA Working Sheets on TZ Testing 2003 ISTA Working Sheets on TZ Testing 2003 PRETREATMENT Soak 18 hours in water at 7 C (to avoid germination) PREPARATION BEFORE STAINING Cut longitudinally through embryo and ¼ of endosperm Remove lemma, cut longitudinally through distal ½ of endosperm

10 COMPARISON PREPARATION STEP Handbook On Tetrazolium Testing, ISTA 1985 Tetrazolium Testing Handbook, AOSA 2000 PRETREATMENT 6-18 hours (soak in water is not mentioned) Imbibe on moist rolled paper towels, overnight, C PREPARATION BEFORE STAINING Longitudinal cut through the midsection of the distal half and tear the nutritive tissues that surround the embryo Longitudinal cut to almost full depth through the midsection of the embryonic axis and into the nutritive tissue Bisect longitudinally completely through seed and retain half for staining Leave seed intact at distal end

11 COMPARISON PREPARATION STEP ISTA Rules 2004 ISTA Working Sheets on TZ Testing 2003 ISTA Working Sheets on Te Testing 2003 STAINING 3 hours, 30 C, 1% TZ-solution 18 hours, 30 C, 1% TZ-solution EVALUATION: AREA OF UNSTAINED TISSUE (NON-VIABLE SEEDS) More than 1/3 radicle, measured from the radicle tip (In total, more than 1/3 distal part of scutellum) More than 1/3 radicle, measured from the radicle tip. In total, more than ¼ distal part of the scutellum

12 COMPARISON PREPARATION STEP STAINING EVALUATION: AREA OF UNSTAINED TISSUE (NON-VIABLE SEEDS) Handbook On Tetrazolium Testing, ISTA hours (temperature and concentration of testing solution are not mentioned) More than 2/3 radicle More than 1/3 of scutellum unstained at either end Tetrazolium Testing Handbook, AOSA hours, C, % TZ-solution Radicle less than completely stained More than 1/3 of scutellum unstained at either end Other details are mentioned

13 EXAMPLES Viable seed Viable seed

14 EXAMPLES Viable seed?

15 EXAMPLES

16 EXAMPLES Non-Viable seed

17 EXAMPLES

18 EXAMPLES

19 EXAMPLES

20 EXAMPLES

21 EXAMPLES

22 THANK YOU