Retrofitting the address sanitizer for rust by program analysis

조규원 성균관대학교 일반대학원 2023 국내석사

Rust는 강력한 타입과 메모리 안전성 보장으로 안전한 시스템 프로그래밍 언어로서 인기를 얻고 있다. 그러나 Rust도 완벽한 메모리 안전을 보장하지는 않는다. "unsafe" 키워드는 보안 대신 유연성을 위해 Rust의 복잡한 제약을 일시적으로 벗어날 수 있도록 한다. 또한, Rust 프로그램은 종종 C/C++ 와 같은 안전하지 않은 언어로 작성된 다양한 코드베이스 구성요소를 포함한다. 이러한 이기종 언어 간의 상호작용은 Unsafe 키워드로 작성된 코드에 더해 Rust의 안전성을 위협한다. RustSan은 Rust 프로그램의 효율적인 테스팅을 위한 AddressSanitizer (ASan)을 최적화하는 디자인이다. 우리는 Rust 기반 프로그램에서 ASan으로 보호된 코드 상당 부분이 Rust의 기본적인 보호에 의해 보호되고 있고 이미 안전한 코드여서 ASan의 보호가 필요 없음을 확인했다. 이를 기반으로 RustSan은 Rust의 언어적 보안을 깨트릴 수 있는 가능성이 있는 코드를 식별하고 이 부분들만 ASan으로 보호한다. 평가에서 RustSan은 sanitizer 오버헤드를 효율적으로 감소시키는 것을 볼 수 있다. RustSan을 사용하여 벤치마크를 수행한 결과, 기존의 ASan에 대비해 일반적인 Rust 프로그램에서 평균 42.2%의 실행 시간 감소를 달성한다. 또한, RustSan의 sanity check의 삭제에 대한 정확성은 Rust 프로그램의 CVE 재현을 통해 검증되었다. Rust is gaining traction as a safe systems programming language with its strong type and memory safety guarantees. However, Rust is not infallible. The "unsafe" keyword allows the programmer to temporarily escape the Rust restrictions to trade security for flexibility. Moreover, Rust programs often embed C/C++ components due to the maturity and diversity of codebases written in these unsafe languages. Such cross-language interaction threatens the security guarantees of Rust in addition to the unsafe Rust portions of programs in Rust. RustSan is a retrofitted design of AddressSanitizer (ASan) for efficient fuzzing of Rust programs. Our observation is that a significant portion of ASan-instrumented instructions in a Rust-based program is redundant when the Rust security guarantees are valid at the site. To this end, RustSan identifies and only instruments instructions that indeed may undermine Rust security guarantees. Our evaluation shows RustSan efficiently reduces the sanitizer overhead. Benchmarking among the general Rust programs with RustSan achieves an average of 42.2% execution time reduction over unmodified ASan. Also, the accuracy of RustSan’s instrumentation trimming is verified through the reproduction of CVEs in Rust programs in addition to our theoretical foundation.

Rust와 C/C++ 격리 연구의 맹점과 안전한 상호작용 모델에 관한 연구

노태현 성균관대학교 일반대학원 2023 국내석사

소프트웨어 시스템이 점점 더 복잡해지면서 소프트웨어 취약점을 줄이고 관리하는 비용도 증가하고 있다. 이 문제를 해결하기 위해 C/C++와 같은 전통적인 언어 대신 Rust 프로그래밍 언어가 제안되었다. Rust는 메모리 안전성을 보장하며, Buffer Overflow, Use-After-Free 및 Null pointer dereference와 같은 긴 역사를 가진 보안 취약점들로부터 해방되게 되었다. 하지만, Rust 또한 항상 안전한 것은 아니며, 예를 들면 가상 주소값을 직접 다뤄야 하는 저수준의 프로그래밍 모델에서는 Unsafe Rust를 통해서 컴파일러 없이 개발자가 코드의 안전성을 검증하도록 하였다. 본 논문에서 주목한 점은 메모리 안전성 보장에도 불구하고, 이전 코드와의 호환성을 유지하거나 중복 개발을 피하기 위해 C/C++로 작성된 라이브러리를 사용해야 하는 경우가 여전히 있고 이를 지원하는 외부 함수 인터페이스(Foreign Function Interface)가 Unsafe Rust의 일부라는 것이다. 엄격한 컴파일 과정을 거치는 Rust 프로그램에 비해 외부 라이브러리의 실행 및 결과에 대해 확신할 수 없기 때문에 이는 당연하나, 최근 언어 간의 위협 모델이 다름을 이용한 공격들이 제시되었다. 이런 유형의 공격에 대한 방어책으로, 안전하지 않은 C/C++ 코드를 Rust 코드로부터 격리하는 기술이 지속해서 연구되고 있다. 본 논문은 앞선 논문들에서 놓치고 있는 맹점에 관해 설명하고 두 언어의 주소 공간을 격리하는 것은 전제조건이 될 수는 있으나 충분조건이 될 수 없음을 보이고자 한다. 상용 프로그램의 코드 예제와 함께 성공적인 격리 기술을 위해 고려해야 할 요점들을 나열하고, 궁극적으로 Rust와 C/C++ 코드 간 안전한 상호작용 모델 연구의 방향을 제시하고자 한다. As software systems become increasingly complex, the cost of reducing and managing software vulnerabilities has also increased. To address this issue, the Rust programming language has been suggested as an alternative to traditional languages such as C/C++. Rust guarantees memory safety, which is a crucial feature for software security, as memory-related errors can lead to security vulnerabilities such as buffer overflows, use-after-free, and null-pointer dereferencing. Despite Rust's memory safety guarantees, there are still cases where libraries written in C/C++ are required for compatibility with older codebases or to avoid redundant development. However, the use of C/C++ code in Rust programs compromises Rust's original guarantees. To tackle this problem, recent studies have been conducted to improve the secure interaction between Rust and C/C++ code by isolating unsafe C/C++ code from Rust code. However, these studies have not explored all areas of the problem, and there are limitations to their approaches. This paper aims to uncover these limitations and suggest future research directions for safe interaction between Rust and C/C++ code. By improving the security of the interaction between Rust and C/C++, we can reduce the risk of software vulnerabilities and improve the overall security of software systems.

Evaluation and defense mechanisms of wheat in response to leaf rust

김민서 Graduate School, Korea University 2020 국내석사

Leaf rust is the most widespread and destructive fungal disease, and outbreaks have always caused considerable losses in wheat yields. Thus, worldwide increases in wheat production depend on the development of leaf rust-resistant wheat varieties. In this study, we evaluated the resistance of forty Korean wheat cultivars to leaf rust at the seedling stage. Only two Korean wheats, Ol and Jonong, were resistant to leaf rust, whereas the remaining thirty-eight Korean wheats were susceptible to leaf rust. The resistant wheat varieties presented larger dry seed weights and higher antioxidant activity in response to leaf rust than the susceptible wheat varieties. No differences in β-1,3-glucanase activity or chlorophyll content between resistant and susceptible wheat varieties were observed. Moreover, the evaluation of leaf rust resistance treated with salicylic acid, jasmonic acid, and absicisic acid was conducted in Keumkang wheat cultivar (Triticum aestivium L.) using modified detached leaf assay, which showed sensibility to leaf rust in whole seedling assay, and showed the most resistance in SA treated wheat. And transcriptional analyses of several genes induced by Lr were investigated by quantitative RT-PCR. Several crucial genes predicted to be involved in leaf rust resistance were confirmed to have increased expression in SA-treated wheat seedling. Overall, these results are important for the development of wheat varieties that are highly resistant to leaf rust and to understand the underlying mechanisms that confer leaf rust resistance.

Genetic Relationship of Adult Plant Resistance to Wheat Rusts and Validation of Stem Rust QTL

Rauf, Yahya University of Minnesota ProQuest Dissertations & T 2019 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Cereal rusts are among the most important fungal diseases worldwide and pose a major threat to global food security. Wheat is attacked by three rusts known as stripe rust, leaf rust, and stem rust caused by fungal pathogens, Puccinia striiformis f. sp. tritici (Pst), Puccinia triticina (Pt), and Puccinia graminis f. sp. tritici (Pgt), respectively. These pathogens are widely distributed across the world, produce spores with the ability to travel long distances, rapidly multiply under favorable environmental conditions, and evolve new races that overcome the resistant genes in cultivated varieties. The rapid appearance of new races of rust pathogens with virulence for the major seedling resistance genes in wheat has intensified the focus to breeding for durable resistance. Durable rust resistance is more likely to be of adult plant resistance (APR) rather than seedling resistance, and not associated with the genes conferring hypersensitive reaction. Two projects were developed to identify and map the genetic sources and dissect the mechanism of APR to rusts. The first project utilized a bi-parental mapping population derived from a cross of COPIO x Apav#1. It consisted of 178, F4:F5 recombinant inbred lines (RIL) developed at the International Maize and Wheat Improvement Centre (CIMMYT) in Mexico. The objectives of this study were to map the APR genes in ‘COPIO’ and to understand the genetic relationship of APR genes conferring resistance to all three rusts. The parents of the RIL mapping population were tested against selected Pgt, Pst, and Pt races at the seedling stage and were also assayed for the known APR genes and 2NS/2AS translocation using molecular markers. The RIL population was also evaluated under field conditions in six environments for leaf and stem rust and nine environments for stripe rust. Genotyping of the population and parents was carried out through genotyping-by-sequencing (GBS) and 762 resulting polymorphic markers each representing a unique locus, were used for the downstream QTL mapping analysis.Molecular characterization and quantitative/qualitative analysis revealed that COPIO harbors some important pleiotropic and APR genes along with qualitative genes for Pgt, Pst, and Pt. Pleiotropic gene Lr46/Yr29/Sr58 on chromosome 1BL reduced disease severities of all three rusts with R2 values ranging from 10 to 42%. The APR genes Sr2/Yr30 for stem and stripe rust along with either a new gene for leaf rust resistance or due to pleiotropic effects of Sr2/Yr30 resulted in reduced severities of all three rusts. The 2NS/2AS translocation segment on chromosome 2AS containing the race-specific resistance genes Sr38, Lr37, and Yr17 is present in COPIO. A new putative stripe rust APR QTL (QYr.umn.2A) in the same region, along with partial effects of Yr17, significantly reduced stripe rust severities in all nine environments. We also postulated the presence of Lr13 on chromosome 2B and Yr31, Yr45, and Yr60 on chromosomes 2B, 3D, and 4B respectively in COPIO. This study also detected minor effect QTL, both previously reported (for stem rust; QSr.umn.3B.2; QSr.umn.4B, for stripe rust; QYr.umn.1A; QYr.umn.3B.3) and potentially new sources of resistance (for stem rust; QSr.umn.2A.3; QSr.umn.7A, for leaf rust; QLr.umn.2A.1, QLr.umn.3B, for stripe rust; QYr.umn.1B.1; QYr.umn.3A.2) in COPIO. These QTLs are also contributing quantitative resistance to all three rusts in COPIO. Our findings show that wheat line COPIO contains pleiotropic, APR and seedling genes along with small to medium effect QTL that are working in combination to enhance genetic resistance against rust pathogens. Broad spectrum resistance against wheat rust diseases in COPIO makes it a valuable source of resistance and its utilization in recombination breeding can potentially enhance durable resistance. Development of diagnostic markers, particularly for the 2A QTL (QYr.umn.2A), will be useful for marker assisted selection in breeding programs.The second project involved a bi-parental mapping population developed by crossing a wheat line ‘MN06113-8’ and cultivated wheat variety ‘Sabin’. The wheat breeding program at the University of Minnesota previously mapped a large effect stem rust APR QTL (QSr.umn-2B.2) on chromosome 2B in wheat line ‘MN06113-8’. This QTL is effective against the North American, Kenyan and Ethiopian stem rust pathogen races. The objectives of this study were to:1) understand the genetics of APR to wheat stem rust in the breeding line ‘MN06113-8’ and cultivated wheat variety ‘Sabin’; and 2) validate 2B QTL in MN06113-8. A total of 184 recombinant inbred lines (RILs) from the cross Sabin/MN06113-8 were tested in stem rust nurseries in Kenya, Ethiopia and Saint Paul. Both parental lines were highly susceptible to Ug99 races TTKSK, TTKST, and TTKTT at the seedling stage but MN06113-8 exhibited adult plant resistance (APR) in Kenya and Ethiopia under field testing conditions. Genotyping by sequencing (GBS) was used to genotype the population and both parents. A total of 4,100 polymorphic GBS markers were assigned to 21 wheat chromosomes to develop the linkage maps. The GBS single nucleotide polymorphism (SNP) markers covered 2,931 cM of the genome with an average of 0.71 markers cM-1 . Composite interval mapping detected six quantitative trait loci (QTL) on chromosomes 2A, 3B, 4A, 4B, and 6B associated with stem rust resistance. Among these seven QTL, three were detected in African environments and four were detected in Saint Paul against the North American stem rust pathogen races. We could not validate QSr.umn-2B.2, discovered in a previous study involving MN06113-8 because the QTL region was monomorphic in our population. A large effect QTL (QSr.umn.3B) was mapped on chromosome 3B conferring resistance to Ug99 and North American Pgt races. The QTL (QSr.umn.4A.1) detected in Kenya on chromosome 4A has not been previously reported. Development of diagnostic markers and pyramiding of these genes through marker assisted selection will accelerate the development of durable rust resistance.

A Comparative Analysis of Rust-Based SGX Frameworks : Implications for building SGX applications

신희경 성신여자대학교 일반대학원 2024 국내석사

The widespread adoption of Intel Software Guard Extensions (SGX) technology has garnered significant attention, primarily owing to its robust hardware-based data-in-use protection. To alleviate the complexities of SGX application development, an approach involving the incorporation of a Library Operating System (LibOS) within an enclave has gained prominence. This strategy enables SGX utilization without necessitating extensive modifications to legacy code. However, this approach increases the potential attack surface and may be susceptible to memory corruption vulnerabilities. To address this challenge, the trend of leveraging Rust programming language offering memory safety guarantees for implementing system components has prompted the development of Rust-based SGX frameworks. But still, a gap exists in providing guidelines or systematic analyses to aid developers in selecting a suitable Rust-based SGX framework, considering factors like implementation cost and runtime overhead. This study undertakes a comprehensive comparative analysis of three representative SGX frameworks implemented with Rust: Rust SGX SDK, Occlum, and Fortanix EDP. Our analysis encompasses an exploration of their internal implementations, focusing on their impact on both performance and security. Furthermore, quantifying the engineering effort for migrating legacy Rust applications and comparing the supplementary overhead incurred when subjecting these frameworks to CPU and memory-intensive workloads are essential aspects of our analysis. Through this examination, the goal is to offer valuable guidance to developers who are in the process of selecting a Rust-based SGX framework that aligns with their application’s specific purpose and workload characteristics. 견고한 하드웨어를 기반으로 사용 중인 데이터에 대해 보호 기능을 제공하는 Intel SGX (Software Guard Extensions, SGX) 기술이 널리 채택되면서 개발자들의 주목을 받고 있다. 특히, 레거시 코드를 수정하지 않고 라이브러리 운영 체제 (LibOS)를 Enclave 내에 이식하는 방법을 통해 SGX 응용프로그램 개발의 복잡성을 줄일 수 있다. 그러나, LibOS 기반 SGX는 잠재적인 공격 표면을 증가시키며 메모리 손상 취약성에 노출될 수 있다. 이 한계를 극복하고자, 시스템 구성 요소를 안전하게 구현하여 메모리 안전성을 보장하는 Rust 프로그래밍 언어를 활용하는 추세이다. 이에 따라 Rust 기반 SGX 프레임워크를 활용한 응용프로그램 개발 방법론이 대두되었다. 하지만, Rust 기반 SGX 프레임워크를 선택하는 것에 있어 구현 비용 및 런타임 오버헤드와 같은 요소를 고려하는 개발자들을 위한 지침이나 체계적인 분석이 미비하다. 본 연구에서는 Rust로 구현된 세 가지 대표적인 SGX 프레임워크인 Rust SGX SDK, Occlum, Fortanix EDP에 대해 전반적인 성능 비교 분석을 수행한다. 이 분석은 성능 및 보안에 미치는 영향에 중점을 두어, 각 프레임워크의 내부 구현을 분석한다. 더욱이, Rust 프로그래밍 언어로 작성된 응용프로그램을 마이그레이션 하는 데 필요한 개발 비용을 양적으로 평가하며, 프레임워크를 CPU 및 메모리 집약적인 워크로드에 적용했을 때 발생하는 추가적인 오버헤드를 평가한다. 이 분석을 통해 개발자들에게 응용프로그램 및 워크로드 특성에 적합한 Rust 기반 SGX 프레임워크를 선택하도록 하는 지침을 제공하고자 한다.

Characterization of Synthesized Carbonate and Sulfate Green Rusts : Physicochemical Properties and Mechanism(s) of their Formation

Su Yeon Choi 고려대학교 대학원 2023 국내석사

GR는 이중층 수산화(layered double hydroxide, LDH) 광물로, 서로 다른 산화 수의 철(Fe)이 팔면체 층을 구성하며, 이로 인해 발생한 전하 불균형을 상쇄하기 위한 다양한 음이온이 층 간에 존재한다. GR 과 같은 이중층 수산화물의 이화학적 특성은 이러한 팔면체 구성 양이온과 층간 음이온의 특성에 크게 좌우되며, 자연계에서 산출되는 GR에서는 탄산염(CO32-)와 황산염(SO42-), 그리고 염화 이온(Cl-)와 같은 이온들이 층간 음이온으로 보고되었다. 이러한 GR의 구조적 특성으로 다양한 음이온 흡착 및 산화 환원 반응을 통한 친환경 고효율 오염정화 소재로서 활용되고 있다. 본 연구에서는 carbonate green rust (CGR)과 sulfate green rust (SGR)를 공침법(co-precipitation)을 통해 각각 합성하고 이들 GR의 화학변화에 따른 이화학적 특성 변화를 비교 분석하여 형성 메커니즘 인자들을 체계적으로 규명하였다. X-선 회절(XRD) 분석 및 리트벨트 정련 수행 결과, 다른 이차광물상이 없는 순수 CGR과 SGR이 합성되었으며, 이들 각각의 구조 파라미터는 CGR의 경우 a축 = 3.17 Å, c축 = 22.53 Å이고 SGR의 경우 a축 = 5.50 Å, c축 = 10.98 Å으로 밝혀졌다. 또한 이들 합성 시료의 미결정크기는 각각 57.8 nm (CGR)과 40.11 nm (SGR)로 관찰되었다. 퓨리에 변환 적외선(FT-IR) 분광 분석결과 CGR과 SGR이 carbonate (CO32-)와 sulfate (SO42-) 분자를 각각 보유하고 있으며 XRD 광물상 동정 결과와도 일치함을 보였다. 뿐만 아니라, 주사전자현미경/에너지분산형 분광분석 (SEM/EDS) 결과, 두 GR 모두 팔면체를 구성하는 철(Fe)과 산소(O)의 함량과 육각 판상의 결정 형상은 비슷하지만 층간 음이온인 탄소(C)와 황(S)의 함량은 각각 서로 다르게 나타났다. 철 용액으로의 수산화 이온 (OH-) 주입 시간에 따른 혼합 용액의 pH와 Eh, 그리고 잔류 철 농도의 비율 (Fe(II):Fe(III)) 측정 결과, 시간에 따른 차이는 있지만 두 green rust 모두 1단계 전구체 형성, 2단계 중간 생성물로의 상전환, 그리고 3단계 green rust로의 상전환과 에이징에 의한 결정성장으로 이어지는 결정 형성 메커니즘을 보이는 것으로 고려된다. 향후 기합성 된 CGR과 SGR의 이화학적 특성 및 형성 메커니즘을 상세 규명하고 영향 인자 변화에 따라 반응 특성 및 이에 대한 메커니즘을 상세히 밝히고자 한다. 이러한 GR 형성 및 이화학적 특성 규명을 통해 이들 광물의 산업 활용에 원천 기초자료를 제공할 것으로 기대된다. GR is a layered double hydroxide (LDH) mineral. Iron (Fe) of different oxidation numbers constitutes an octahedral layer, and various anions exist between the layers to offset the charge imbalance caused by this. Physicochemical properties of double-layered hydroxides such as GR are largely dependent on the properties of these octahedral cations and interlayer anions. Carbonate (CO32-), sulfate (SO42-), and chloride (Cl-) ions have been reported as interlayer anions. Due to the structural characteristics of GR, it is used as an eco-friendly and highly efficient contamination purification material through various anion adsorption and redox reactions. In this study, carbonate green rust (CGR) and sulfate green rust (SGR) were synthesized through co-precipitation, and the physicochemical properties of these GRs were compared and identified to systematically determine the formation mechanism factors. As a result of X-ray diffraction (XRD) analysis and Rietveld refinement, pure CGR and SGR were synthesized without any other secondary mineral phase, and each of these structural parameters was a-axis = 3.17 Å, c-axis = 22.53 Å for CGR, and a-axis = 5.50 Å, c-axis = 10.98 Å for SGR. In addition, the crystallite sizes of these synthetic samples were observed to be 57.8 nm (CGR) and 40.11 nm (SGR), respectively. Fourier transform infrared (FT-IR) spectroscopic analysis showed that CGR and SGR had carbonate (CO32-) and sulfate (SO42-) molecules, respectively, and were consistent with XRD mineral phase identification results. In addition, as a result of Scanning Electron Microscope/Energy Dispersive Spectroscopy (SEM/EDS), both GRs have similar iron (Fe) and oxygen (O) contents and hexagonal plate-shaped crystal shapes constituting the octahedron, but the contents of carbon (C) and sulfur (S), which are interlayer anions, were different from each other. As a result of measuring the pH and Eh of the mixed solution and the ratio of residual iron concentration (Fe(II):Fe(III)) according to the injection time of hydroxide ion (OH-) into the iron solution, although there is a difference with time, both of two green rusts are considered to show crystal formation mechanism(s) leading to the formation of precursors in step 1, phase conversion to intermediate products in step 2, and phase conversion to green rust in step 3 and crystal growth by aging. In the future, the physicochemical characteristics and formation mechanism of pre-synthesized CGR and SGR will be investigated in detail, and the reaction characteristics and mechanism(s) thereof will be revealed according to the change of influencing factors. Through this GR formation and physicochemical characterization, it is expected to provide basic data for industrial utilization of these minerals.

Effects of sodium silicate on the expression of leaf rust resistance gene in wheat

이가현 Graduate School, Korea University 2022 국내석사

밀은 주식으로 널리 소비되는 가장 중요한 곡물 재배와 곡물 작물 중 하나이다. 밀잎녹병은 일반적으로 잎에서 발견되는 가장 흔한 밀 질병 중 하나로 수확량과 영양성분의 상당한 손실을 초래할 수 있다. 실리콘(Si)은 일반적인 식물에 필수적인 요소로 간주되지 않지만 곰팡이와 박테리아 병원체에 대한 성장과 방어 체계에서 추가적으로 유익한 요소로 간주된다. 본 연구에서는 국산 밀 재배종(금강, 우리, 다홍)을 선정하여 세 단계 농도(50mM, 100mM, 200mM)의 규산나트륨으로 처리하였다. 실리콘 트랜스포터와 Lr10, Lr26의 발현도를 비교하여, 잎녹병에서 규산나트륨이 밀의 유전자 발현에 미치는 영향을 RT-PCR에 의해 연구하였다. Si가 직접적으로 유전자 발현의 차이를 만들지 않았지만 밀이 잎녹병에 감염되었을 때, Si 처리는 유전자 발현 정도에 차이를 보였다. 세 품종 모두에서 Si 처리의 녹병 저항성 증가 효과 관찰되었다. 결론적으로 밀의 녹병 저항성을 증가시키기 위해 Si 처리가 긍정적으로 작용한다는 것을 제안한다. Wheat is one of the most important cereal crops widely consumed as a staple food. Wheat leaf rust is one of the most prevalent wheat diseases generally found on the leaves and could lead to a significant loss of yields and nutrient contents. Silicone (Si) is not considered an essential element for general plants but an additionally beneficial element in the plant growth and defense system against fungi and bacterial pathogens. In this study, wheat cultivars (Keumkang, Uri, and Dahong) were selected and treated with sodium silicate at three levels (50 mM, 100 mM, and 200 mM). Comparing the expression of silicon transporters (TaLsi1) and leaf rust resistance (Lr10 and Lr26), the effect of sodium silicate on the gene expression of wheat in leaf rust disease was studied by qRT-PCR. The results of the present study showed that Si was not directly related with gene expression of Si transporter but Si treatment affected a difference in gene expression in times of wheat infection by leaf rust. In all three cultivars, the effect of Si treatment was observed to increase the rust resistance. In conclusion, it is suggested that Si treatment affects positively to increase the rust resistance of wheat.

Breeding for Yield Stability of Corn Hybrid through Multi-environment Trials in East Timor and Korea : 동티모르와 한국에서의 다중환경 검정 시험을 통한 교잡종 옥수수의 수량 안정성 육종

Nabais, Claudino ninas 경북대학교 대학원 2010 국내박사

옥수수는 여러 선진국가와 개발도상국의 경제발전에 있어 중요한 역할을 해 온 작물이다. 한국과 동티모르에서 각각 노균병 (Peronosclerospora sorghi) 와 녹병 (Puccinia Polysora Underw.) 저항성 다수확 사일리지 옥수수 품종 육성을 실험을 2년간 실시 하였다. 실험재료는 경북대학교 유전자원센터 유전자원과 동티모르 유전자원을 이용하였다. DM 저항성과 non-DM 계통들은 각각 동티모르의 Loes 연구센터에서 2008년 12월과 2010년 2월에 시험 검정하였다. 또한 단친계 선발에 의한 NAI를 육성시도를 하였다. NAI는 동티모르 5군데 지역에서 30여 개의 농가확대 실험을 하였다. 6개 조합의 사일리지1호와 사일리지 2호는 경북 군위, 제주도 그리고 경기도 안성에서 연중 재배실험 하였다. 재배실험은 3반복 완전임의배치 하였고 농가확대 시험구는 대조품종과 함께 각각 하나의 시험구로 배치하였다. 식물체 간장, 착수고, 이삭길이, 입수 및 이삭직경, 이삭무게, 건조중량 그리고 노균병과 녹병 저항성 등 농업적 형질을 수치화하여 검정하였다. 실험수치는 SAS 9.1(2005) 프로그램으로 분석하였다. Loes 에서의 시험구 검정을 통해 노균병 저항성이 있는 계통들을 선발하였다. 교배조합별로 노균병 저항성에 대한 고도로 유의한 변이가 있었다. TZSTR 109 x NAI(ET-18), (Maek x DMR) x Suwan 5(ET-29), (1010 x ET bulk) x TZSTR(ET-31 과 ET-32), Suwan 5 x TZi 25(ET-36) 등의 교배조합S4 세대들은 노균병 저항성이 있었다. 2010년 실험결과 TL-37(ET-39 X Suwan 5)과 TL-33(ET-21 X Suwan 5)는 동티모르 적응형 다수확 단교잡종으로 선발 되었다. 첫번째 NAI 농가 확대실험결과10지역 중 6군데에서 우수한 상품성(Co.V.)이 검정되었다. NAI의 생산량은 1ha당 7.3t으로 1ha 당 5t의 Arjuna보다 고도로 유의하였다. 2006년 군위에서 발견 된 새로운 녹병 저항성에 대해69B X P45와 51B X P45 등이 고도로 유의하였다. 사일리지 1호와 사일리지 2호의 제주도와 군위에서의 녹병 저항성 정도는 다른 수치로 조사되었다. 사일리지 2호는 최고 저항성 수치가 제주도와 경북대학교 실습농장 에서 각각 4.1과 4.2로 조사 되었다. J2-16 (1034(P45) x 1227(51B)), J2-31 (1038(P45) x 1227(51B)), J2-56 (1057(P45) x 1206(51B)) 등은 제주도에서 저항성 정도가 평균 2.7이었다. J2-1 (51B-2 x P45-11), J2-8 (51B-3 x P45-26), J2-15 (51B-29 x P45-8), J2-39 (51B-48 x P45-95) 등은 경북 군위에서 저항성 정도가 평균 3.0이었다. 사일리지용 옥수수 품종의 수량 형질에 관련하여, 간장은 J4-6 (P45-74 x 51B-2), J4-43, J2-69 (51B-29 x P45-8), J2-71 (51B-29 x P45-21), J4-42 (P8038 x 51B-8033) 등이 최고의 평균치로 조사되었다. 곡물수량과 건조중량 형질에 관련하여 J4-44 (P45 x 51B-8033)가 가장 높은 수치로 조사되었고, J4-40 (P45-4 x 51B-12), J2-76 (51B-8034 x P45-8039)등의 조합들이 다음으로 높은 수치였다. J2-43 (51B-16 x P45-2)은 최대 알맹이 수량형질 조합으로 조사되었으며, J2’-42 (51B-8006 x P45-8053), J2-1 (51B-2 x P45-11), J4-43 (P45-8038 x 51B-8033) 등은 최대 건조중량형질 조합으로 조사되었다. AS1-24, AS1-20, AS1-23, AS4-26 등은 경기도 안성에서 건조중량이 평균치 17.3이었다. 고도의 노균병 저항성 그리고 녹병 저항성 품종 육성에는 어려움이 따르지만 환경과 상호작용을 고려하여 양적 유전형질 이용한 품종 육성은 가능하다고 사료 되어진다. Corn (Zea mays L.) has contributed greatly on economic development for many developed and developing countries. We have carried out two-year round of multi-environment experiments on tolerant and high yield cultivars for downy mildew (DM) (Peronosclerospora sorghi) and Southern rust (Puccinia Polysora Underw.), and high yield of corn silage in East Timor and Korea. Materials of experiments were obtained from KNU Gene Bank and local races. Two sets of DM resistance (R) and non-DMR lines were tested at Loes Research Station, East Timor in December 2008 and February 2010. Meanwhile, we also developed the first cycle of “NAI” by using half-sib selection. The composite seeds were tested in 30 on-farm demonstrations in 5 different locations. Six sets of Silage 1 (69B x P45) and Silage 2 (51B x P45) were tested for year-round in Kunwi, Jeju and Ansong. All experiments were designed in RCBD with 3 replications, except on-farm demonstrations were carried out in one plot with checks. Data assessment was done toward the important agronomic traits such plant height (PH), ear height (EH), ear length (EL), kernel row length (KRL), ear diameter (ED), ear weight (EW), dry matter (DM), DMR and Southern rust resistance. Data was analyzed with SAS 9.1 program (2005). The result showed that at Loes Research Station, DMR trials of two sets were confirmed. Genotypes showed highly variation for DM infection. S4 crosses of TZSTR 109 x NAI (Entry No. ET-18), (Maek x DMR) x Suwan 5 (Entry No. ET-29), (1010 x ET bulk) x TZSTR (Entry No ET-31 and ET-32) and Suwan 5 x TZi 25 (Entry No 36) exhibited tolerant to DM infection. The result of 2010 trial with Entry No. of TL-37 (ET-39 x Suwan 5) and TL-33 (ET-21 x Suwan 5) showed high yield potential for hybrid corn for East Timor. Six of 10 on-farm demonstrations of the first cycle of NAI exhibited outstanding for commercial value (Co.V.). Grain yield of NAI was highly significant different than Arjuna with 7.3 t ha-1 and 5 t ha-1, respectively. Meanwhile, in Korea, genotypes of two sets of 69B x P45 and 51B x P45 tested in Jeju and Kunwi showed highly significant different (P=0.001) for the new disease of Southern rust. The new disease of Southern rust was found at Kunwi Farm in 2006. The mean of Silage 1 and Silage 2 for Southern rust infection at two locations in Jeju Island and Kunwi showed varied. The highest mean rate was Silage 2 with 4.1 and 4.2 in Jeju and at KNU Farm, respectively. Genotypes with the highest rates were Entry No. J2-16 (1034(P45) x 1227(51B)), J2-31 (1038(P45) x 1227(51B)) and J2-56 (1057(P45) x 1206(51B)) with average 2.7 in Jeju Island. In Kunwi, the highest rates were Entry No. J2-1 (51B-2 x P45-11), J2-8 (51B-3 x P45-26), J2-15 (51B-29 x P45-8) and J2-39 (51B-48 x P45-95) with average 3.0. For corn silage, the highest rate for PH was Entry No. J4-6 (P45-74 x 51B-2) followed by J4-43, J2-69 (51B-29 x P45-8), J2-71 (51B-29 x P45-21) and J4-42 (P8038 x 51B-8033). J4-44 (P45 x 51B-8033 was the highest grain yield and dry matter followed by the Entry No. J4-40 (P45-4 x 51B-12), J2’-76 (51B-8034 x P45-8039). Entry No. J2-43 (51B-16 x P45-2) was the highest rate for grain yield. Entry No. J2’-42 (51B-8006 x P45-8053), J2-1 (51B-2 x P45-11) and J4-43 (P45-8038 x 51B-8033) were for the highest rate for dry matter. In Ansong, AS1-24, AS1-20, AS1-23 and AS4-26 exhibited highest rate of dry matter from the Mean: 17.3. Our breeding experiences showed that to breed highly resistance to DM and Southern rust is difficult. However, breeding for host tolerance with polygenic system with a threshold nature is possible.

Translating C to Safe Rust: Reasoning about Pointer Types and Lifetimes

Emre, Mehmet University of California, Santa Barbara ProQuest D 2022 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Infrastructure software is written in low-level programming languages like C to allow precise control of resources. However, C lacks safety features to ensure memory and thread safety. These safety issues result in serious security vulnerabilities or unreliable behavior. Rust is a programming language that provides the same fine-grained control with automatically-checked safety measures. Rust is being adopted by some large C and C++ code bases such as Linux, Firefox, and Chromium. However, proving a program's safety to the Rust compiler requires non-local reasoning about ownership and lifetimes of objects in the program so translating C programs to safe Rust programs is nontrivial.This thesis presents the challenges in translating C programs to safe Rust programs, along with a categorization of different classes of unsafety. To kick-start automated translation from C to safe Rust, I present a novel method to infer object lifetimes and ownership using the compiler as an oracle. I then develop an evaluation methodology to measure the potential impact of this method independent of other causes of unsafety in the program. With this methodology, I show that the efficacy of this method (along with any potential method to discover existing safe uses of objects in the program) is limited by the precision of the type system when propagating unsafety information. Then, I investigate the impact of more sensitive data flow analyses to curb the spread of unsafety, and show that they can be encoded by transforming the program without changing the type system. Overall, the findings of this thesis are that(1) the causes of unsafety are intertwinend, (2) using the compiler errors to derive lifetime information is effective for discovering existing safe uses of objects, (3) imprecision of the type system leads to excessive spread of unsafety (as lack of provable safety according to the compiler), and (4) this can be mitigated by transforming the program to make the results of a more precise analysis available to the type checker.

Sources of FHB Resistance, Genetics and Mapping of Stem Rust Resistance in Kenyan and Ethiopian Spring Wheat Germplasm

Kosgey, Zennah Chepkoech ProQuest Dissertations & Theses University of Minn 2019 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Fusarium head blight (FHB or scab) and stem rust are important diseases of wheat. Fusarium graminearum is considered the primary causal agent of FHB. This study evaluated 215 wheat genotypes from Kenya and Ethiopia for their response to F. graminearum in inoculated and mist-irrigated nurseries established in St. Paul, MN in 2016, St. Paul, MN in 2017 and Crookston, MN in 2017. Six genotypes with stable resistance across the three test locations were identified. Positive associations were identified between FHB index, VSK, and DON and negative associations were identified between FHB index, plant height, and heading dates. The response of select genotypes was confirmed under greenhouse conditions. These studies identified resistance sources that can be used to improve the resistance levels in Kenyan and Ethiopian wheat germplasm. Stem rust caused by Puccinia graminis f. sp. tritici remains a threat to wheat production in East African wheat growing regions. In this study, we characterized the genetics of stem rust resistance, identified QTLs and markers associated with the resistance in spring wheat line CI 14275. The RILs together with their parents were evaluated at the seedling stage in a biosafety level 3 greenhouse against Pgt races TTKSK and TRTTF and in the USDA-ARS Cereal Disease Lab greenhouse against Pgt races TPMKC, TTTTF, and RTQQC. Screening for resistance to Pgt races in the field was undertaken in Kenya, Ethiopia, and the US in 2016, 2017, and 2018. One and three complementary genes conferred resistance to races TTTTF and RTQQC, respectively. The QTL QSr.cdl-2BS.2, that conferred resistance in Kenya and Ethiopia was validated and the marker Excalibur_c7963_1722 was shown to have potential in marker assisted selection. This is the first study to both detect and validate an adult plant stem rust resistance QTL on chromosome arm 2BS. The QSr.cdl-3B.1 is likely Sr12, QSr.cdl-4AL.1 is postulated as Sr7a, QSr.cdl-6BL.1 is likely Sr11, and QSr.cdl-6AS.1 appears to be a new QTL. Combination of QSr.cdl-2BS.2, QSr.cdl-3B.1, and QSr.cdl-6AS.1 has the potential to reduce stem rust severity in Africa. The work presented on FHB and stem rust provides resources for wheat improvement in East Africa.