Accomplishments

 

Floral Biology

Protogyny in Indian mustard: Protogynous (Pg) plants were identified from different open pollinated cross combinations in F5 generations. The duration of protogyny ranged up to 11 days in timely sown conditions while it was reduced to 5 days in late sown conditions. In protogynous flowers, pollen viability was more after 3 days of anthesis compared to younger and older flowers. All protogynous flowers were self incompatible that could be overcome by spray of IAA/GA3/Hisidine/Kinetin of different doses at weekly interval during the flowering period.

 

Stigma receptivity in bitter gourd: varies with the seasons and is for one day during spring-summer season and more than a day during kharif season. In both the seasons the stigma receptivity was maximum between 8AM to 12 PM and starts decreasing gradually afterwards reaching the lowest at 6PM. Pollen viability will be at its maximum (>90%) during morning hours and, thereafter it decreases gradually. Pollens can be stored for 3 days at 300C. Fresh pollens were more effective in setting the fruits.

 

Stigma receptivity in wheat: Maximum stigma receptivity was observed during 5 days after secondary floret opening in wheat CMS lines (HW 2022, HW2041, HW2046). The stigma receptivity was maximum upto 5 days, wherein the seed set % ranged from 40% to 74% in various CMS lines (HW 2022, HW2041, HW2046); after which the receptivity declined, leading to as low as 2% seed set on ninth day.

 

Seed Production

Planting ratio for hybrid seed production: For seed production of CGMS based mustard hybrid NRCHB-506, planting ration of 8:2 (A:R) is recommended by which an average of 1.5t/ha hybrid seed could be harvested.  For hybrid seed production of wheat, planting ratios (female: male) of either 2:1 or 3:1 were found more economical.

Chemical treatments for higher seed production: In bitter gourd hybrid seed production, spraying the female parent with GA3 (@ 50ppm) at 3 leaf stage+ tendril initiation+ bud initiation enhances the number of pistillate flowers, fruit and seed setting, fruit weight and seed yield. Bitter gourd hybrid seed production technology under net house condition was worked out, which can give seed yield of 1.8 kg/100 m2.

Harvesting method for higher seed quality: In Anise (Pimpinella anisum) seed crop, the seeds harvested from primary and secondary umbels were better in quality (high germination and vigour) than that harvested from tertiary and quaternary umbels.

 

DUS Testing

Description: DSCN9163DUS Database: has been generated for 98 farmers’ varieties based on 49 field morphological characters as per DUS test guidelines showed some easily distinguishable characters, viz. shattering behaviour in Randhunipagal and Laalnita; very shrivelled seed in Ramsal; and black lemma tips in Kalanunia and Kalobhutia.

 

 

 

 

Seed Testing and Certification
Seed standards: It was developed for Carum carvi L. (Caraway) and Nigella sativa L. (Kalonji).


Seed quality attributes

Standard for each class of seed

Carum carvi L. (Caraway)

Nigella sativa L. (Kalonji)

Foundation Seed

Certified Seed

Foundation Seed

Certified Seed

Pure seed (min.)

97.0 %

97.0 %

99.0 %

99.0 %

Inert matter (max.)

3.0 %

3.0 %

1.0 %

1.0 %

Other crop seed (Max.)

10 / kg

20 / kg

None

5/kg

Total weed seed (Max.)

10 /kg

20 / kg

None

None

Objectionable weed seed (Max.)

None

None

None

None

Germination (Min.)

50 %

50 %

65 %

65 %

Moisture (Max.)

8.0

8.0

10 %

10 %

Moisture for vapour-proof containers (Max.)

6.0

6.0

8.0 %

8.0 %

 

Protocols for seed testing: Conditions for testing the seed germination in Carum carvi L. (Caraway) has been standardized.Top of the Paper method (TP) is recommended with optimum germination temperature of 20/30 0C and light requirement for 16 hrs and dark requirement of 8 hrs. First count of germination is at 12 days and final count at 28 days. Treating seeds with GA3 or prechilling of seeds for 3-4 days before conducting the germination test overcomes the problem of fresh ungerminated seeds due to non-deep physiological dormancy. Tz (Topographical Tetrazolium Chloride) test for early estimation of the viability status of Carum carvi L. (Caraway) seed lot has been standardized.

Molecular markers for ensuring seed purity: Molecular markers for ensuring the hybrid seed purity in cotton (DCH32 and RAHB87), maize (Vivek Hybrid-9, PEHM-2, HM-11, Vivek QPM-9 and HQPM-1), Pearl millet (RHRBH8609, RHRBH8924, GHB538, GHB732, GHB744, GHB719, GHB558, PUSA605, PUSA23 and HHB67) and Brinjal (PH 5, PH 6, PH 9, NDBHL 21, Kashi Komal and Kashi  Sandesh) has been identified. The reliability of identified molecular markers in comparison to Grow Out Test for ensuring the hybrid seed purity has been established. Seed crushed supernatant-based PCR assay for ensuring the genetic purity in crops has been developed, which reduces the cost of DNA extraction to the extent of 90% and was amenable to multiplex PCR method. This protocol was validated in different crops like paddy, pearl millet, mustard, cotton and soybean. Restorer gene specific SCAR marker is validated for ensuring the purity of mustard hybrid NRCHB-506 and its R line. Three-mitochondrial gene anchored TRAP markers were identified for testing the purity of A line against admixture of B line for A1 cytoplasm, which was also validated using the A1 CMS lines in different nuclear backgrounds.

 

 

 

 

Seed Quality Enhancement

Seed priming: Maize seed hydration for 17 hrs at 25 0C followed by dry dressing with Thiram (@ 3g/Kg of seed) improves field emergence, speed of emergence, early seedling and vegetative growth, seedling root growth, chlorophyll content, plant height and seed yield.

Seed treatment: Spot blotch of wheat can effectively managed through seed treatment by Carboxin (37.5%) + Thiram (37.5%WS) @2.5gm kg-1 seed + two foliar sprays of Propiconazole 25 percent EC @0.1per cent (one at boot leaf stage and another 20 days after 1st spray).Brown spot of paddy can effectively controlled through seed treatment by a combination fungicide containing Carboxin 37.5% and Thiram 37.5% WS @2.5 gm kg-1 seed at the time of nursery seeding, Seedling dip in suspension of Pseudomonas flourescens @ 10gm/ litre before transplanting followed by two sprays of Propiconazole 25% EC @0.1% at 45 days and 60 days after transplanting.

 

Seed Physiology

Basics of seed priming: In maize seed hydro priming improves membrane integrity of hydrated seed which manifests in reduced electrolyte leakage and water-soluble sugar in steep water. An insight into the biophysical basis of maize seed priming treatments revealed that these treatments modified seed water-binding properties as concluded by seed absorption, desorption patterns and seed water activities. The better performance of primed seeds could be attributed to better availability of free water for metabolism and cellular activities. Seed germination studies of hydrated seeds revealed that the activities of hydrolytic, respiratory and antioxidant enzymes were higher and the peaks were induced early in treated seeds than that in control seeds.

 

Description: Enzyme activity graphDifferences in speed of germination: During the triphasic imbibition, the lag phase II in low vigour seeds is very long in comparison to that in high vigour seeds. This results in differential behavior with respect to speed of germination (radicle emergence) in paddy. When low vigour seeds were primed, the speed of germination increases, which is attributed to increased activity of galactomannan hydrolyzing enzymes.

 

Seed Pathology

Bipolaris oryzae : One hundred and sixteen isolates of Bipolaris oryzae were isolated and purified from collected diseased specimens of rice samples. Based on the morphological variability viz., conidial structures, conidial dimensions, colony diameter, the isolates were grouped into different categories.