K. D. Kofoid

Genetic analysis of feed quality and seed weight of sorghum inbred lines and hybrids using analytical methods and NIRS

Eight lines of grain sorghum and their F1hybrids were evaluated for contents of crude protein (CP), fat (FAT), and starch(STA); protein digestibility (PD); and in vitro dry matter disappearance (IVDMD).The effect of seed weight (SW) on these traits and the potential use of near infrared reflectance spectroscopy (NIRS) to predict them also were investigated. The male lines included three normal-seeded lines (TX2737, TX435, and P954063) and two large-seeded lines (PL-1 and Eastin1). The female lines included common U.S. seed parent lines (Wheatland, Redlan, andSA3042). The lines and their hybrids were grown under dry land conditions at Kansas State University experiment fields in Ashland and Belleville, Kansas, in 1999.The experiments were conducted using a randomized complete block design with four replications at each location. The effect of genotype was significant for all measured traits. The male parent lines were highly variable and expressed high levels of genetic variation in combining ability for CP, PD, STA, and SW. The female parents were genetically more uniform; however, significant general combining ability effects were noted for PD and SW. Significant negative correlations were noted between CP and STA and between SW and STA. Significant positive correlations were found between CP and SW and between FAT and IVDMD. Crude protein content was predicted accurately by NIRS. Fat content and IVDMD could not be predicted by NIRS. The NIRS equations based on ground samples were more accurate than those based on whole-seed samples.

Genetic Analysis of Kafirins and Their Phenotypic Correlations with Feed Quality Traits, In Vitro Digestibility, and Seed Weight in Grain Sorghum

ABSTRACT Twenty-three entries of grain sorghum (Sorghum bicolor (L.) Moench), including eight inbred lines (five males and three females) and 15 hybrids, were evaluated to determine the proportion of γ, αII, and β-αI-kafirins and their association with contents of crude protein, fat, and starch; protein digestibility; in vitro dry matter disappearance; and seed weight. The male lines included three normal-seeded lines (TX2737, TX435, and P954063) and two large-seeded lines (Eastin1 and PL-1). Female lines consisted of three common U.S. seed parent lines (Wheatland, Redlan, and SA3042). The lines and their hybrids were grown under dryland conditions at two locations in Kansas using a randomized complete block design. The effects of genotype, location, and males were significant for all kafirins. Wide variations in composition and general combining ability (GCA) for kafirin content were noted among parent lines and hybrids, with TX2737, Eastin1, and PL1 having the largest GCA values for γ (1.37), αII (1.99)...

Haploidy in sorghum

Haploid plantlets can be produced through various means (Clapham, 1977). However, haploid production using anther or microspore culture is amenable to many dicotyledonous and monocotyledonous crop species. The doubled haploid breeding scheme has advantages in accelerating and simplifying procedures for production of homozygous plants. Haploid cell suspension culture can also be used to screen for stress tolerance. In addition, callus, cell suspensions, or protoplasts derived from haploid cells can be used as recipients in transformation either by cocultivation with Agrobacterium or by a biolistic gun.

Variability and relationships among 12-hour IVDMD, starch, oil, protein, and physical characteristics of 16 sorghum conversion lines

A factor frequently identified as a key to understanding sorghum [Sorghum bicolor (L.) Moench feed value to ruminant animals is rate of starch digestion. Recent research in corn (Zea mays L.) has established a strong ability to predict rumen starch degradation from grain physical and chemical parameters. It was therefore important to determine whether similar relationships could be established in sorghum. The objectives of this study were to determine: 1) range of variation for12-hour in vitro dry matter disappearance (IVDMD), chemical, and physical grain quality parameters among 16sorghum conversion lines; and 2) to establish the strength of the relationships of these characters. Entries were grown at Ithaca, Nebraska in 1991 and 1992 in a randomized complete block with four replications. Line effects were significant for 12-hour IVMVD, crude protein, oil, starch, individual seed weight, and hardness. The only traits significantly correlated with 12-hour IVDMD were crude protein and hardness, with r≤–0.32 for testa and non-testa-containing lines. Stepwise regression similarly revealed poor predictive ability for any of the traits on12-hour IVDMD. Unlike corn, prediction of digestibility from simply measured physical parameters was not possible in this set of16 sorghum lines. However, the lack of strong relationships provides opportunity to select lines with unique combinations of traits for individual targeted needs or markets.