Popcorn Breeding Populations
For use as Genetic Stocks by Popcorn Breeders - based upon availability
BSP9SGC0 is a yellow-kernel popcorn breeding synthetic developed to be a source of popcorn inbred lines with high-popping expansion and good agronomic traits. It was developed by intermating twenty-five experimental popcorn inbred lines. Four of these lines were derived from HPSGDS-2, a dent-sterile Supergold popcorn population released by Purdue University, and the remaining twenty-one lines were derived from recurrent selection cycles 1 to 3 in BSP2C1 released in 1988 and then again in 1999 as BSP2C4. At each generation in the development of the lines and then in the development of BSP9SGC0, selections were made for increased popping expansion on a single ear basis.
BSP9SGC0 is a relatively narrow genetic based yellow-kernel popcorn breeding synthetic related to the Supergold popcorn heterotic group. It has a relatively small range in maturity in that all pollinations made for seed increase in 2003 were made on the same day, 5 days before HP72-11 was at midsilk. In 2002, 215 ears were selected to intermate and then increase in 2003 for a 2004 release. The 215 ears had an average popping expansion of 1544 ml/30g with a range of 1167 ml/30g to 1720 ml/30g. Popcorn check hybrids Iopop12 averaged 1278 ml/30g and Rob97487 averaged 1660 ml/30g. Kernel size averaged 58 k/10g with a range of 46 to 75 k/10g with popcorn check hybrids Iopop12 at 73k/10g and Rob97487 at 63 k 10g. Expansions per kernel averaged 8.0 ml/k with a range of 7 ml/k to 11 ml/k with the check hybrids Iopop 12 averaging 5.3 ml/k and Rob 97487 averaging 8.7 ml/k.
Although BSP9SGC0 was not rigorously screened, it should be nearly 100% dent sterile and carries good agronomic traits. It should be an excellent source for high expansion Supergold dent sterile inbred lines.
BSP7SAC0 is more closely related to South American types than to Supergold or Amber Pearl types and represents the ISU popcorn breeding program's improved South American population.
BSP8SGC0 is more closely related to Supergold types than South American or Amber Pearl types and represents the ISU popcorn breeding probram's improved Supergold population.
Both yellow-kernel popcorn populations are variable for all traits and have improved popping expansions. Though not rigorously tested, the populations should be dent sterile. During development of these populations, selection was also made for tolerance to European corn borers.
500 k packets are available for $50.00 each. Signed research and development agreements are required.
The following synthetic stocks are available at $50 for 500 kernels, postage paid. A brief description of each follows:
Identification: BSP4APC0, a random mating yellow-kernel popcorn synthetic
Description (Taxonomic): Zea mays L. Yellow-Kernel popcorn population variable for all traits with a strong tendency to tiller.
Performance Summary: The 154 open pollinated ears selected from 534 harvested ears to generate this released population had single-ear popping expansions that averaged 50.6 cc/g and ranged from 62.0 cc/g to 38.7 cc/g. Popcorn popping check hybrids Iopop12 and Rob20-70 averaged 42.6 cc/g and 57.3 cc/g, respectively.
Identification: BSP5C0, a random mating yellow-kernel popcorn population
Description (Taxonomic): Zea Mays L. Yellow-kernel popcorn population variable for most traits. Most of the plants tend to be tiller free. At a very low frequency, some kernels will mutate to soft endosperm.
Performance Summary: The 151 open-pollinated ears selected from 859 harvested ears had single ear popping expansions that averaged 54.2 cc/g and ranged from 64 cc/g to 35 cc/g. Popcorn popping hybrid checks Iopop12 and Rob20-70 averaged 42.8 cc/g and 56.9 cc/g, respectively.
This is a genetically diverse, yellow-kernel population of adapted popcorn germplasm. It was developed by allowing many of the most popular and newest popcorn hybrids, both yellow and white, to random-mate via open pollination. During these two intermating generations--open pollination in isolation--mass selection was practiced for standability. After this, a recurrent selection program using S1 lines for evaluation was initiated to improve the population. This released population is cycle 1 of that recurrent selection program.
In 1985, an evaluation of the population per se at two locations, one near Ames, Iowa, and one near Lafayette, Indiana, indicated respective stalk breakage percentages of 4 and 5. This population was included in 2 popcorn hybrid yield tests where the respective overall stalk breakage percentage averages for the hybrids were 6.3 and 9.3. Thus, this population can serve as a source of inbred lines with improved standability. Popping expansion for the population was 41.0 at both locations with the averages of the hybrids in the two experiments at 41.7 and 41.3, respectively. Also, an evaluation of the population per se in 1985 (2 reps) gave an average rating of 3.5 and 4.0 for first and second generation European corn borer resistance, respectively, on a scale of 1 to 9 with 1 being resistant and 9 being susceptible. Evidently, this population can serve as a source of some resistance to both generations of the European corn borer.
Initial checks indicate that, although the population is mostly dent sterile, it is not 100 percent dent sterile.
BSP1C4 is an improved recurrent selection cycle 4 version of BSP1C1. BSP1C1 was released in 1986 and described in Crop Science, 1987, 27: 1318-1319. Through the additional three cycles of S1 recurrent selection, BSP1C4 has undergone selection for improved popping expansion, improved stalk quality, and increased tolerance to the second generation of the European corn borer (ECB). It is a yellow-kernel popcorn population variable for plant height, kernel size and shape, flake type, and maturity. The 100 plants selected to generate the population had no broken stalks and 1994 single-ear popping expansion averaged 56 cc/g and ranged from 61 cc/g to 37 cc/g while the standard large popping check hybrid, Rob20-70, averaged 54 cc/g. BSP1C4 should be nearly 100% dent sterile. It seems to be most closely related to South American Types.
BSP1C4 is available as a royalty free general public release. Seed cost is $50 / 500 kernels.
This is a somewhat narrow, genetically-based yellow population of adapted popcorn germplasm. It was developed to provide a source of large expansion inbred lines to cross to inbred lines coming out of dent corn x popcorn germplasm. Inbreds derived from dent x popcorn germplasm generally have improved stalk quality but poorer popping expansion.
Four popcorn hybrids, A3004, 33122, P203, and 62180 were intermated in a diallel fashion. A3004 is a private hybrid from Ames Seed Farms, P203 is a released hybrid from Purdue, and 33122 and 62180 are nonreleased Purdue experimentals. A3004 and 33122 were chosen for their large popping expansion, 62180 for its excellent stalk strength, and P203 because its pedigree includes inbred lines found in the other hybrids.
In 1987, self-pollinated ears from the population were evaluated for popping expansion. These 285 ears averaged 1,254 ml/30g with a range of 600-1,580. Popping expansions for the hybrid checks were: Iopop 12 = 1,212, A3004 = 1,345, M140 = 1,394, and Rob 30-71 = 1,440. Of the 285 ears, 23 had popping expansions above 1,440. Also in 1987, European corn borer (ECB) data were collected on the performance of the population per se. The population per se averaged a rating of 2 for first-generation European corn borer resistance and a 4 for second-generation resistance on a scale of 1 to 9 where 1 is resistant and 9 is susceptible. It appears that along with large popping expansion, the population also carries fair resistance to both generations of the European corn borer.
Inbred lines developed from this population should be dent sterile.
BSP3C1 is a yellow-kerneled popcorn synthetic that has dent corn germplasm in its background. The dent corn lines used were B86, B87, B68, and B84. The popcorn lines used were IDS69, IDS91, and KP47R, giving it a South American popcorn background. BSP3C1 is mid-season maturity under Ames, Iowa, growing conditions. It has excellent agronomic traits. Dry microwave popped 30-gram expansions for the 250 ears bulked to form the synthetic ranged from 30 cc/g to 58 cc/g with an average of 49 cc/g. Hybrid checks A3004 and Rob20-70 averaged 47 cc/g and 50 cc/g, respectively. The population per se averaged a visual rating of 6, and 6 for resistance to first- and second-generation of the European corn borer (ECB), respectively, where a rating of 1 is resistant and 9 is susceptible. It is dent sterile (Gals-Gals) and has a kernel per 10 gram count of 62.
This is a genetically diverse, white-kernel population of adapted popcorn germplasm. It was developed by allowing many of the most popular and newest popcorn hybrids, both yellow and white, to random-mate via open pollination. During these two intermating generations--open pollination in isolation--mass selection was practiced for standability. Then, white kernels were separated from yellow, and an S1 recurrent selection program was initiated within the white material to improve the population. This released population is cycle 1 of that recurrent selection program.
A 1985 evaluation of the population per se at 2 locations, one near Ames, Iowa, and one near Lafayette, Indiana, for standability gave a mean of 7.5 percent for stalk lodging. This population was included in a 6-entry white hybrid yield test where the mean stalk lodging was 16.6 percent. Thus, this population could prove to be a source of improved standability for white popcorn. In the same test, this population had an average popping expansion of 39.9 with the overall mean of the test at 39.0, so it appears this population has an acceptable level of expansion.
An evaluation of the population per se in 1985 (2 reps) gave an average rating of 4 and 4 for first- and second-generation European corn borer (ECB), respectively, on a scale of 1 to 9 with 1 being resistant and 9 being susceptible. Evidently, this population can serve as a source of some resistance to both first- and second-generation European corn borer for white popcorn.
Initial checks indicate that, although the population carries the gene for dent sterility, it is not 100 percent dent sterile.
BSPM1C1 is a fairly broad, genetic-based population of adapted yellow-kernel popcorn germplasm. It was developed to provide a source of popcorn germplasm that carries the tendency to pop a high percentage of "mushroom" or "ball" type flakes. The population has been through one cycle of S1 recurrent selection for the ability to pop large mushroom flakes. During its development, it was crossed to dent sterile material such that the population should be cross sterile (Gal-S Gal-S).
In 1989, sib-pollinations were made in the population to increase seed for release. On a rating scale of 1 to 3 where 1 is a high percentage of mushroom flakes and 3 is 100 percent butterfly flakes, 143 of 221 ears rated a 1. Of these 221 ears, only 7 produced 100 percent butterfly flakes. The 100 ears selected to generate the released population all rated a 1 with a popping expansion equal to or greater than our mushroom check hybrid A5011.
The population per se under Ames, Iowa, growing conditions appears to be mid-season maturity with good agronomic traits and large kernel size. It popped 37.5 cc/g while our A5011 hybrid check popped 37.0 cc/g.
BSPM2C1, a yellow-kerneled popcorn synthetic that has dent corn germplasm in its background, is a mushrooming sub-population of BSP3C1. BSPM2C1 was developed to provide a heterotic partner population to BSPM1C1 for producing inbred lines that combine to produce mushroom hybrids. This synthetic is mid- to full-season maturity under Ames, Iowa, growing conditions. It has excellent agronomic traits. Oil popped 30-gram popping expansions for the 250 ears bulked to form the synthetic ranged from 17 cc/g to 39 cc/g with an average of 29 cc/g while mushrooming checks A5011 and BSPM1C1 averaged 25 cc/g and 27 cc/g, respectively. It is dent-sterile (Gals-Gals) with relatively large kernel size (kernels/10 gram = 53). Because is still carries some dent kernel characteristics, lines from this population should be used as males when crossed to lines from BSPM1C1 to develop mushroom hybrids. The population per se, evaluated in 1991, rated a 5 and 7 for resistance to the first- and second-generation European corn borer (ECB), respectively, where 1 is resistant and 9 is susceptible. The population cross, BSPM1C1 x BSPM2C1, rated a 5 and 6, respectively.
This population is Iowa State's version of Purdue University's HPXD-1 population after 2 cycles of recurrent selection for popping expansion. The original HPXD-1 has excellent stalk quality traits but only average popping expansion. In order to improve the expansion of this population, intense selection pressure for high expansion was applied throughout the 2 cycles of recurrent selection.
The decision to release this cycle of HPXD-1 was based on 2 factors. The first is that expansion improvements were made with no loss in standability. The second is the expansion data on individual ears from this population. In 1989, sib-pollinations were made in the population to increase seed. These individual sib-mated ears were popped and 18 out of 240 had expansions comparable to Rob30-71, our high expansion hybrid check. Also, to start the next cycle of recurrent selection, self-pollinations were made and 9 of these 226 ears had expansions comparable to Rob30-71. It appears that, even though the average expansion of cycle 2 was only 4 percent greater than the expansn of cycle 0, some relatively high expansion lines can be selected from cycle 2.
Except for a slight loss in yield, there appears to be only minor changes in agronomic traits between cycle 0 and cycle 2.
BSP2C4 is cycle 4 of an S1 recurrent selection program using the previously released population BSP2C1, Crop Science. 1990. 30:238-239, as the base population. BSP2C4 is more closely related to Supergold types than either South American or Amber Pearl types. This yellow-kernel population also has improved stalk quality traits and popping expansion.
BSP6CBC0 is the result of intermating 10 selected lines from cycles 1, 2, and3 of BSP1C1 and 10 selected lines from an experimental synthetic released in 1996 as BSP5C0. This Population is more closely related to South American types than either Supergold or Amber Pearl types and most plants have high ear placement. BSP6CBC0 also carries a higher level of natural tolerance to the second generation of ECB than probably any other adapted popcorn breeding synthetic.
BSP8SGC0 is more closely related to Supergold types than South American or Amber Pearl types and represents teh ISU popcorn breeding program's improved Supergold population. Both yellow-kernel popcorn populations are variable for all traits and have improved popping expansions. Though not rigorously tested, the populations should be dent sterile. During development of these populations, selection was also made for tolerance to European corn borers. License agreements with ISURF are required for this variety prior to purchase.
BSPM3C0 is a population cross between BSPM2C1 and a suspopulation in the breeding program that showed a strong tendency to pop mushroom flakes. The cross was made to broaden the genetic base of BSPM2C1 for the mushrooming trait.